Readability tips, literacy news, and English writing advice

The Coleman-Liau Index

Developed in 1975 by Meri Coleman and T. L Liau, the Coleman-Liau Index remains one of the most commonly used readability formula. But how are scores from the test generated? And what value is the Coleman-Liau in helping us to measure how easy or hard different texts are to read?

What is the Coleman-Liau Index?

The majority of classic readability measures such as Flesch-Kincaid and Gunning Fog involve counting the number of syllables per word and per sentence. Yet, a distinctive feature of the Coleman-Liau Index is that the formula does not involve any counting of syllables. Back when they introduced their measure over forty years ago, Coleman & Liau (1975) argued that despite developments in the area, techniques designed to estimate number of syllables lacked accuracy. This they saw as a key weakness of existing readability formula. For instance, if we consider the word going we know that this word has two syllables. Yet, the word boing, identical to going apart from the starting letter, has only one syllable. Differences such as these are very difficult for a machine to detect. Indeed, syllable counting by humans, let alone by machines, is far from an exact science. The challenges to counting syllables are something we will be exploring in an uncoming article.

Aside from issues over accuracy, one of Coleman & Liau’s key criticisms of existing readability formula was that syllable counting required the time intensive process of “keypunching the text into the computer”. Now, in the midst of the digital era, this criticism has rather lost its edge. But, Coleman & Liau’s argument about the inaccuracy of syllable counting remains valid.

According to Coleman and Liau, "There is no need to estimate syllables since word length in letters is a better predictor of readability than word length in syllables." Further, designing a “mechanical device” that could count sentence length and word length, with word length measured in letters not syllables would be easy and accurate.

By basing calculations on the number of letters in a word and number of words in a sentence, readability scores measured by Coleman-Liau Index may be seen as more accurate than those measured by formula that rely on syllable counting.

How does the test work?

So, as we’ve said, the formula involves no syllable counting.

The building blocks used in the formula are:

L = average number of letters per 100 words and;

S = average number of sentences per 100 words.

The formula is as follows:

0.0588L – 0.296S – 15.8

Making sense of the results

The Coleman-Liau formula estimates the years of formal education the reader requires to understand the text on first reading. So, if a piece of text has a grade level readability score of 6 then this should be easily readable by those educated to 6th grade in the US schooling system, i.e. 11-12 year olds. Text to be read by the general public should aim for a grade level of around 8.

Scores generated by the Colmean-Liau formula are sometimes reported to be lower than other readability formula such as Flesch-Kincaid when applied to technical documentation.

When is the test most useful?

The original Coleman-Liau paper identifies organisations such as the US office for Education and the Library of Congress as potentially benefiting from the Coleman-Liau Index as it will provide them with an easily calculated, economical measure of readability. This suggestion is in line with the roots of readability formula, originally developed to allow standardisation of textbooks for the public school system.

The Coleman-Liau Index is now used widely used across a range of sectors and topics. As well as being used to measure the readability of educational materials for schools, the Coleman-Liau has also been used to measure readability of patient education documents, to evaluate online reviews, and to help identify the source language of literary translations.

While the Coleman-Liau is widely used, the Index is often administered alongside other readability measures with researchers taking a blanket approach to measuring readability administering a batch of well-known tests with the Coleman-Liau among them. But, one are where the Coleman-Liau holds particular value is in measuring readability of texts written in non-English languages of Western-European origin. For these non-English texts, the Coleman-Liau provides a marker for comparison of ease of reading. So, by running the test on two different texts, e.g. two German newspapers, the test results would allow you to see which textbook is harder or easier than the other.

There are limitations of the applicability of Coleman-Liau to non-English texts. Importantly, the grade level that the test generates is standardised on English language texts. Other Western-European languages such as Spanish and German differ syntactically and in comparison to the English language, make use of more compounded words. This results in the common use of longer words which, unlike long words in the English language, are familiar and not deemed as difficult words for native speakers. When the Coleman-Liau formula is applied to non-English texts, the number of letters in the word would make, for instance, a German text generate a high readability score not reflective of the actual level of education the reader would require in order to understand the text. So, for non-English language texts, the grade level is meaningless, i.e. the score will not reflect the grade level of the text analysed. The value of Coleman-Liau Index for non-English texts then is in the comparison between texts rather than the meaning of the individual scores.

One case in which Coleman-Liau was identified as useful was in a study exploring which readability tests are suitable for the Norwegian language. In this research, readability grade level results were compared across different tests for the same text. Based on the differences in use of multi-syllable words in Norwegian compared to English, the researchers concluded that they would not recommend tests that use syllables and complex words as a part of the calculation. Instead, Coleman-Liau and Automated Readability Index – another test that is calculated using the number of letters in words rather than syllables – were recommended and were found to behave most consistently across the research.

Another interesting avenue for the Coleman-Liau measure is in the study of law and courts. Here, the measure has been used to explore the readability of judicial opinions. These are legal opinions written by judges during a court case to provide a decision reached to resolve a legal dispute.

Researchers report that when trying to pass a decision which is inconsistent with the majority position of members of congress – equivalent to members of parliament in the UK -, judges will strategically write less readable opinions. The researchers drew their conclusion based on measurement of the readability, using Coleman-Liau, of over 500 randomly selected Supreme Court majority opinions. By making their opinions harder to read, the researchers argue, judges help to protect the court from criticism from members of congress. Writing harder to read opinions will make it more difficult and time consuming for congress to backlash against the decision.

  • The Coleman-Liau Index remains a steadfast player in the measurement of readability.
  • The defining characteristic of the Coleman-Liau is that it does not involve syllable counting
  • The Coleman-Liau Index is suitable for assessing comparative readability of non-English, Western-European texts.

Feeding Your Ego - When To Use 'Me' or 'I'

We all know that person who insists they are a grammar king or queen and corrects someone who uses 'me' at the end of a sentence. "You mean 'Grandma gave presents to my cousins and I,'" they say, with not an even inkling in their mind that their might be wrong.

Both 'me' and 'I' are pronouns, but that doesn't mean they are interchangeable. In fact, by the rules of English grammar there are specific times to use each one. So how do you know when to use which of these two pronouns?

In technical terms, as explained by the Oxford Dictionary, you should use 'I' when the pronoun is the subject of a verb and you should use 'me' when it is the verb's object.

Okay, great, that's the technical explanation, but when you're in the middle of a crowded bar trying to prove your correction-friendly acquaintance wrong, how do you explain it in a way other people will understand? Try this trick: remove the other people/subjects from the sentence. Let's look at a couple examples.

"My dog and me ate ice cream yesterday." Remove "dog" and what are you left with? "Me ate ice cream yesterday." It's pretty clear that's wrong! So this is an instance where you would need to change 'me' to 'I.' Let's look at another one:

"My mother joined my father and I for dinner." Remove "father" and what do you have? "My mother joined I for dinner." Nope. Make that a 'me!'

Use this simple deletion and substitution trick, and you'll find yourself becoming a pronoun usage expert in conversation and in writing.

How To Use Common Latin Abbreviations

Latin abbreviations are quite common in standard English, but they are also commonly misused. Here are some popular examples, what they mean, and how to use them correctly.

1. etc.

Of course, etc. stands for et cetera, meaning "and the rest" or "and others." Use etc. to indicate a continuing list of things that don't need to be specified. When using etc., do not begin your list with a phrase like "such as," which already indicates that your list will be incomplete.


"I packed sandals, towels, sand toys, etc., into the trunk."

"I packed the trunk with sandals, towels, sand toys, etc."

As shown above, use a comma before and after etc. when it falls mid-sentence. When using etc. at the end of a sentence, the period that ends etc. will also end the sentence, unless you want the end punctuation to be something other than a period:

"Did you bring sandals, towels, sand toys, etc.?"

Friendly note: The phrase is ET cetera. "ECK cetera" is incorrect and, frankly, a little embarrassing.

2. e.g. and i.e.

When you've named a broad category of things and wish to give an example or two, you may use e.g., which means exempli gratia, or "for example."

When you've used a word or phrase that the reader may not fully appreciate without clarification, use i.e. (id est) to mean "that is to say" or "in other words." Often, i.e. is used to impart an extra layer of meaning.


"Karen hopes to enter a caring profession, e.g., nursing or psychology."

"Julia wants to be in real estate or finance, i.e., a profession with high earning potential."

3. a.m. and p.m.

We know these abbreviations indicate whether a time is before (ante) or after (post) the noon hour (meridian), but should they be capitalized, and should we use periods?

As with i.e. and e.g., the standard in American grammar is to use lowercase letters with periods after each. However, the standard in English grammar outside the U.S. is to omit the periods. When writing for an institution or business, find out if they have a preferred style. Consistency in usage is, in these cases, more important than personal conviction.

Confusion over whether "12 a.m." or "12 p.m." is correct is simply handled; use the words "noon" and "midnight" instead. This principle applies to the other abbreviations as well; when in doubt, feel free to use the English phrases they represent. In fact, when your writing task calls for formal language, the use of abbreviations may be discouraged.

The best way to internalize language rules is to consider many examples and explanations. Browse various grammar sites and visit this space often for useful usage tips, interesting insights, and learned language!

The Dreaded Semicolon

Never has a punctuation mark been so feared as the semicolon. Semicolons are an excellent choice for writing if you give them half a chance. Consider them super commas ready to do the heavy lifting a comma cannot.

When There Are Two or More Independent Clauses

If you are writing a short sentence, and you put another short sentence about the same topic behind it, you can use a semicolon. It's grammatical freedom like none other.

I enjoy using advanced punctuation; it really elevates my composition game.

Use a semicolon in place of a comma and a conjunction or an end mark to impress your friends and family.

When There is Internal Punctuation

Not all independent clauses are created equally. Use a semicolon when punctuation appears internally in a sentence.

Lately, I've been feeling like my grammar is on point; I would like to flex my grammatical muscles with semicolons.

If a comma was used to separate these clauses, it would result in a comma splice. This is a perfect instance for a semicolon.

When There is a List of Items Separated with a Comma

Commas are wonderful for lists of small items, but sometimes writers need an option for lists of objects that contain commas within the list.

I have been to Houston, Texas; Seattle, Washington; and Lincoln, Nebraska.

I enjoy using semicolons in lists; using commas sparingly; and using proper grammar when I write.

Letting semicolons into your world will open up all kinds of possibilities. Use them with independent clauses, clauses with internal punctuation, and lists with commas. Go ahead and increase your composition skills today.

Four Spanish Words That English Really Needs

Spanish is a language spoken all over the world, in North America, South America, Europe, and hundreds of countries. It's estimated that over 400 million people speak Spanish worldwide. In schools in America, it's one of the most popular languages offered in schools.

But there are some words in Spanish that we don't have an English equivalent for. Words with deep, strong meanings that we cannot say as simply as they do.

1. Encantar

Encantar in English means multiple things. It is often used to express charm, extreme like, and sometimes love. In English there are six similar words: love, enchant, delight, charm, captivate and bewitch.

2. Tutear

Tutear is a way to address someone, but while it is not completely informal, it is not as formal as it could be. There is no real was to say this English at all, only a way to describe it.

3. Te Quiero

Te Quiero is an in-between phrase- it does not literally mean "I love you" (that's Te Amo), but it does not mean "I like you" either. The closest translations are "I really like you" or "I desire you".

4. Sobremesa

Sobremesa is a word used to describe the period of time after dinner where all the food is all gone, everyone has finished eating, but the conversation is still flowing, so no one leaves the table.

There are many of other words Spanish speakers know but cannot translate easily into English. Hopefully someday English speakers will have words similar to these words, and many more we can't easily explain.

English: It's All Greek To Me

Democracy, Technology, Logic, Energy ... what do all of these words have in common? An ancestor in Ancient Greece. All throughout the English language, particularly in the realms of medicine, science, art, and politics, we find words built out of pieces of an ancient past.

Imagine you are a language archaeologist (there's another one!). You are digging through ruins, finding broken pieces here and there, and suddenly you discover there is a pattern to the pieces: they fit together. Even better, they fit together in hundreds of different ways, and each combination means something new and different.

That is what it is like to discover the Greek 'pieces' that combine to form so many English words. Here are just a few that a language archaeologist might find while digging through Ancient Greek:

  • Philos: Love, affection
  • Sophia: Wisdom
  • Logos: Word, Study, Knowledge
  • Bios: Life
  • Graphia: writing

Pick up 'bios' and click it like a Lego brick to 'logos' and you have biology, the study of life. Take off 'logos' and click on the 'graphia' piece, and you have biography, 'writing of life.' Tack 'logos' to the end of 'psyche' (mind and soul) and you have psychology. Click 'philos' and 'sophia' together to make Philosophy, literally the 'love of wisdom.' Afraid of heights? Attach 'akro,' Greek for 'high,' to 'phobos' (the name of the Greek god of Fear), and you have a name for that: acrophobia. What do you call a government controlled by its people? Well, how about linking up 'demos' (the people) to 'kratia' (power or rule)? That works, right? Need a word for a sleepy trance? How about borrowing the Greek god of Sleep's name? He's called Hypnos.

Once you get started it's hard to stop, and you're finding the pieces everywhere, switching them around and trying new combinations until suddenly you're surrounded by thousands of words. Cardiology. Telephone. Thermal. Microscope. Automobile. Geology.

Because Ancient Greek isn't actually spoken anymore, it's called dead, or extinct (as is Latin, which is another abundant source of English words).

But is it? It's not used in conversation anymore (Modern Greek, even though it shares the same alphabet, is an almost completely different language), but we could say that it lives on in English, which has taken so many words from so many languages and made them its own.

So quick! What does 'philology' mean?

Long "Lives" the Queen?

If you live in the English-speaking world, the odds are high that you've heard, or maybe even used, the expression, "Long Live the Queen." There's a special feeling to the phrase, isn't there? Not because of the content of the phrase itself, but because of its texture as it's spoken. It's as though it belongs to a foreign or earlier set of English rules, not quite your own. It just feels a little -- off.

After all, grammatically, it's a bit of a perplexity. Why "live," and not "lives?" If we were to reorder the phrase, we would certainly say, "The Queen lives long." So, what are we actually saying when we use this phrase? Is there a reason for this strange verb form?

It turns out that there is, and it's called "Subjunctive Mood." The Subjunctive Mood can be found in many languages. As its name may hint, it is a mood which expresses subjectivity. In other words, the Subjunctive is how we might express our own emotions, judgments, or uncertainties when discussing a situation. This may sound difficult to get a hand around, but in fact, English-speakers instinctively use this grammatical mood all the time, mostly to express strong desire for something.

An everyday example: "I would prefer that you be on time," as opposed to "I would prefer that you are on time." There are very few, if any, instances in which the latter would or could be used -- and you, as an English speaker, already knew this!

Often, in English, the Subjunctive mood is hidden. The form of the verb usually doesn't even change. Between "I call my mother daily," and "it is important that I call my mother daily," can you tell which is Subjunctive? Although the modified verb, "to call," looks the same in both, it's only in the second phrase that it is Subjunctive. An exception to this frequent pattern is the verb "to be," which when modified changes from "I am" to "I be," or "You are" to "You be," as in the example shown above.

One other common exception is the "he/she" form of most regular verbs. In the Subjunctive mood, "she gives" becomes "she give." "He calls" becomes "He call." At this point, you can probably see the pattern: With the Subjunctive mood, the 's' is dropped from the end of "he/she" verb forms.

Now that you know the basic rules, go out and use them freely! Long live the Subjunctive!

Four Eponymous English Words

In any language, words both evolve and are created out of thin air. It is not unusual for a certain person or place to become associated with a trend, item, or invention and for that name to then become a common word in a language. These words are called 'eponyms' and the English language has several examples. Here are four:

1. Sandwich

Why not start with the most delicious of the eponyms? The Earl of Sandwich was an avid cardplayer (ahem, gambler), and he wouldn't leave the table for his meals. Instead, he would eat a piece of meat served between two slices of bread, an easy meal to hold in one's hands without a lot of extra silverware cluttering up the playing table. As the story goes, his fellow cardsharks came to so closely associate this meal with the Earl they started asking for a 'sandwich.'

2. Gerrymander

A much less appetizing word than sandwich, 'gerrymander' is the process of apportioning legislative districts in such a way as to be politically beneficial to one party or another. The name results from legislation signed by Massachussetts Governor Elbridge Gerry that resulted in a salamander-shaped district in the Bay State. Combine Gerry + Salamander and you get both a compound word and an eponym!

3. Saxophone

It just sounds cool, right? Like the name just makes sense? The instrument's name didn't just appear out of thin air, though! It's named for its inventor, Adolphe Sax. We can just assume he was pretty hip.

4. Diesel

Rudolf Diesel gives his name to this form of gasoline and engine. He invented the diesel engine in the early nineteenth century, and while he might not be widely remembered his name is widely used to this day.

If you dig further, you'll find plenty of other examples of eponyms in the English language. If you're interested in finding more, we recommend looking in the science sector, as inventions and discoveries lend themselves well to eponyms.

Four More Words That English Really Needs

The English language is beautiful, complex, and sometimes unwieldy. Even with its nuance and vast selection of words, however, the English language has gaps where other languages don't. Sometimes the human condition and our complicated world just need a word that English doesn't have. Here are four words from other languages that we either need to adopt or establish our own version of:

1. Tartle

What a novel idea - a word for a situation that nearly everyone has found themselves in!Tartle is that point in time where you forget someone's name, but you're supposed to be saying the name, most often in introduction. In English, we just call it awkward, but "tartle" has a much nicer ring to it, don't you think?

2. Cernes

Ever been tired and had bags under your eyes? You're human, of course you have. But in France, you wouldn't need to use four words to describe the unsightly look of a night without sleep. The French simply call those dark circles "cernes."

3. Tsundoku

Have a pile of books you've owned forever, keep adding to, but have never read? If you live in Japan, you'd be committing tsundoku, a very useful Japanese word for the book hoarders in the world.

4. Mencolek

April Fools Day must be wild in Indonesia. They have formal words for classic tricks! Mencolek is the Indonesia word for what in English we are forced to call "the lame prank where you tap someone on the wrong shoulder but are really on the other side so they look and don't see anything but immediately know what happened because that is literally the oldest trick in the book." Mencolek is much more efficient to say, don't you think?

English, for all your charm, you can make things just a little too complicated sometimes. These four words are only a few of the probably hundreds, if not thousands, of examples of words foreign languages simply do better than English.

Four English Words That Have Two Opposite Meanings

The English language can be very strange indeed. In fact, it's so strange that there are many words which have two meanings (at least) and those meanings are the opposite of each other. How's that for confusing? This phenomenon is so common in English that it even has two words to describe it - auto-antonyms and contronyms. Here are four common contronyms that you've probably used:

1. Cleave

You can either "cleave to" something, or cleave something off. Think of a cleaver - a giant knife you use to cut something apart. If you come across a person discussing cleaving you, pay attention to the preposition they are using - they're either a stalker or a serial killer. Or, for all you optimists, maybe they're perfectly nice and just have an odd way of speaking.

2. Dust

When you dust the furniture you are removing the dirt and grime from it, right? But what if you're a baker and you're dusting a cake with powdered sugar? You're not taking it off, you're putting on a dust-like substance (albeit a much tastier one). Children's book character Amelia Bedelia was once famously thrown off by this contronym when she literally threw dust onto her employer's furniture.

3. Garnish

If you've ever had your wages garnished, you know its not a good thing. Your wages are certainly not being added to, rather money is being taken away from you. To the contrary, if you are garnishing a dish you are adding pretty features to it, perhaps a jaunty kale leaf or an orange peel. However, if your spouse has a dish that looks better than yours you might be excused for garnishing a chunk of that lobster from their plate...

4. Clip

A barber clips your hair, in fact he has a tool named after this action (clippers, naturally). In this sense, clip means to remove hair from you. You can also clip coupons to remove them from the newspaper inserts. But, because English is complicated, you can clip papers to hold them together. You can clip your hair back to make it stay in place, and you can clip a cellphone to your belt to look super cool.

English is strange, and it can be complicated. But it never ceases to be fun to explore - even if you have to pay special attention to context and prepositions to make sure words don't literally mean the opposite of their intended use.

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