Here's the basic idea:
An idiom like “Make yourself at home” is rather tricky if you stop to think about it: the imperative verb “make” is followed by a second-person reflexive pronoun (“yourself”) and an adverbial phrase (“at home”), but it’s difficult to break the phrase into its components. Instead, we grasp the whole thing at once.
Ritualized moments of everyday communication — greeting someone, answering a telephone call, wishing someone a happy birthday — are full of these canned phrases that we learn to perform with rote precision at an early age. Words work as social lubricants in such situations, and a language learner like Blake is primarily getting a handle on the pragmatics of set phrases in English, or how they create concrete effects in real-life interactions. The abstract rules of sentence structure are secondary.
In recent decades, the study of language acquisition and instruction has increasingly focused on “chunking”: how children learn language not so much on a word-by-word basis but in larger “lexical chunks” or meaningful strings of words that are committed to memory. Chunks may consist of fixed idioms or conventional speech routines, but they can also simply be combinations of words that appear together frequently, in patterns that are known as “collocations.” In the 1960s, the linguist Michael Halliday pointed out that we tend to talk of “strong tea” instead of “powerful tea,” even though the phrases make equal sense. Rain, on the other hand, is much more likely to be described as “heavy” than “strong.”
My question is, do we learn foreign languages the same way? I know I tend to pick up chunks and use them frequently. For instance, where I once said "Necesito hacer ... [algo]" now it's "Tengo que hacer..." It's just a phrase, you hear it enough it gets into your usage. It's heavy rain instead of strong. More thoughts on this to come.