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  • Writer's pictureSeb Falk

Comprehensible input: vocabulary vs. grammar

Updated: May 12, 2020

What is “comprehensible input“?  What’s just the right amount of it to be able to learn a language?  What’s the relative importance of vocabulary and grammar in making input comprehensible?  And why do I always forget the word for “forget“?

I’ve spent the last month working almost exclusively on learning Classical Arabic.  It’s a tough language for a native English speaker. Obviously it has a different alphabet and little common vocabulary – I look back fondly to my Spanish-learning days, restaurante, política, incendio and all that – but the learning process is also complicated by the fact that the formal classical language is quite different from that spoken every day.  It’s not as different as, say, Latin is from English (or even from Spanish), but it is different enough to make talking with taxi drivers depressingly difficult.

In order to learn, I’m largely reliant on input in classes and from books, as well as the small number of other media that use the formal fussha version of the language.  Fortunately (honestly!), the school where I’m studying gives us plenty of homework – every week we have a whole list of vocabulary to take away and memorise.  The words and phrases in that list are defined only in Arabic, which not only forces us to think carefully about their meanings but also, more often than not, requires more new words to be learnt just to make the definitions comprehensible.

The problem is that most of the vocabulary isn’t that relevant to my purposes.  I’m studying Classical Arabic in order to be able to read medieval astronomical texts, whereas most people on this course are Muslims or Islamic Studies students who would like to be able to understand the Qur’an, Hadith and other early religious texts.  So the vocabulary we have been learning, and the texts we read, have been tailored towards these subjects.  In the last few weeks I’ve learned the words for prayer mat, betrothal, and a battle at which the Prophet Muhammad was (or was not) present, as well as many different words for morality.

Have I not bothered learning this vocabulary, because it doesn’t suit my purposes perfectly?  Of course not (pardon the double negative).  I’ve made a big effort, for three reasons.  First, I always do as I’m told.  Secondly, surely no learning is a waste, and you never know when a word will come in useful.  But thirdly and most importantly, learning the words makes the class input comprehensible – essential for acquiring the language.

What is comprehensible input?  Put simply, it’s the idea that if all the foreign language you encounter is on a spectrum from completely comprehensible (for you) to completely incomprehensible, the perfect level for you will be somewhere in the middle.  If you understand nothing, you’ll learn nothing, but the same is true if you already understand everything.  The best situation is if you understand the gist of an utterance but not every word.  You will be able to absorb the meanings of the previously unknown words (imagine if you understood the gist of the previous sentence but not the word “utterance” – you’d probably guess what it meant with little or no thought).

The theory of comprehensible input (about which you can read more on the excellent LanguageSurfer blog) goes along with another theory (also credited to Stephen Krashen): that a distinction can be made between language acquisition and learning.  The former is an instinctive but slow process; the latter requires conscious effort.  The former is what you’re doing if you read that sentence above and absorb the meaning of the word “utterance”; the latter might involve reading a grammar book and making notes.  And, says Krashen, the former is superior – it’s the only way you can really know a language, rather than just knowing about it.  (Again, see LanguageSurfer for more on this).

Grammar fans may of course protest that understanding the structure of of a language is just as crucial to knowing it as knowing its vocabulary.  I don’t know about that – many native speakers don’t have the first clue about the structure of their own language and get on fine most of the time (at least until they try to teach it).  But it’s surely true to say that for a foreign-language learner, a solid knowledge of grammar can only help with language acquisition.  If I know from my grammar studies that the muta prefix and i vowel in the Arabic word muta’allim make it the active participle of Form 5, from the Form 1 root ‘alima, meaning “to know”, and I know that Form 5 typically expresses the result of Form 2, which itself tends to indicate causation of Form 1 (so that Form 5 ends up being a gradual version of Form 1), then I might be able to guess that muta’allim means a learner or apprentice – though it’s more often used in an adjectival sense, as “educated”.  (If you’re interested, the Form 2 verb ‘allama means “to teach”.)

This post is already getting quite long – so time to wrap up what all this has taught me about language learning.  The first thing to say is that vocabulary must be the most important part of learning a language.  If you want to ask the way to the railway station, no amount of grammar will help you if you don’t know any of the relevant vocabulary (though you can always imitate a train, something I enjoy doing at every opportunity).  Secondly, I’ve learned much here about how vocabulary builds on itself.  If you know a few words in a sentence, you’ll be more likely to learn other words.  I suffered in the first few weeks here because my vocabulary was very poor, but as I learned some of the words the teacher uses regularly (sometimes this had to be through the conscious process of looking them up in a dictionary), I was able to pick up others with less effort.  And finally, there’s no substitute for using new vocabulary in as many contexts as possible.  No matter that I mainly just want to read classical texts: hearing, writing and speaking are all important ways to drive content into my brain, and it is much easier to learn vocabulary by using it in some kind of context than by memorising lists of words.

And why I always forget the word for “forget”?  I forget the answer to that one.  It might have something to do with the weak letter root, but more probably it’s just my defective brain.

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