Using correct collocations makes your English sound natural and fluent. Saying 'do homework' instead of 'make homework' sounds more natural.
Pro Tip 2/3
Fixed Expressions
Some collocations become fixed expressions and can't be changed without sounding odd. We say 'fast food', not 'quick food'.
Pro Tip 3/3
Cultural Nuances
Collocations can vary by English-speaking region, reflecting different cultural references. Americans may say 'take a rain check' while Brits would not.