Michael McCarthy has published an article on using collocations on the Cambridge University ELT blog.
McCarthy says, “Collocations are pairs of words that occur regularly together, with a high degree of probability. They don’t have to be used next to one another; they just have to occur in the same environment. Here are some examples:
She has blond hair. His hair is dyed blond.
She drives a beige car. His car is a sort of light beige.
The internet has played a crucial role in globalisation. The role played by the internet in globalisation has been crucial.
We say that blond collocates with hair and words connected with hair (tresses, curls). Beige can collocate with lots of nouns (car, jacket, wallpaper, floor-covering, etc.) where blond does not (we don’t say a blond car or a blond jacket). On the other hand, we don’t say beige hair. We say that decisions, roles, factors can be crucial, but we do not normally say a crucial man/woman. Collocations reveal restrictions on which words can go together and which words do not”.