R&UoE Part 1 in Depth

If you look up 'heavy' in a learner's dictionary, you'll find a confident, helpful definition: of great weight; difficult to lift. None of that, however, will tell you why English speakers say 'heavy rain' and 'heavy traffic' but not 'heavy wind' or 'heavy temperature'. The dictionary defines words; it does not — at least not visibly — describe their social lives. This is the territory of collocation: the company words keep. Some collocations are nearly fixed: you do research, you make a decision, you take responsibility. Others sit on a sliding scale of acceptability: 'a marked improvement' sounds natural and faintly formal; 'a noticeable improvement' is also fine; 'a big improvement' is acceptable but plainer; 'a strong improvement' is wrong, although a learner could be forgiven for trying it. For a C1 candidate, the implication is unsentimental. Vocabulary knowledge is no longer measured by how many words you can define. It is measured by how reliably you produce the right combinations under pressure. This is why Multiple Choice Cloze tasks rarely turn on dramatic differences in meaning — all four options usually mean roughly the same thing — and almost always turn on collocational fit. The test is not 'what does this word mean?' but 'which of these words actually lives with the words around it?'. The good news is that collocations can be learned, just slowly and in pairs. Reading widely helps. Noticing rather than guessing helps more. And, irritatingly for the impatient student, time helps most of all.