When reading, I’m always confused with idioms, slang and colloquial words. Please tell me how to distinguish them.
An idiom is al fixed phrase the meaning of which bears no relation to the meanings of the individual words that make up the phrase. Phrasal verbs can often have literal or idiomatic meanings:
The teacher told me to sit up. (= sit upright: non-idiomatic)
We’re going to sit up all night during the general election.
(= not go to bed: idiomatic)
Apart from phrasal verbs, there are numerous expressions which are idiomatic. For example:
John imagines he’ll be a millionaire before he’s 25, but that’s just pie in the sky. (= wishful thinking which is impossible to achieve)
Deal with the problem now. Remember, a stitch in time saves nine. (=When something goes wrong, deal with it immediately before it gets worse.)
l Colloquial language is the informal language of everyday speech; slang is colloquial language which is so informal, and often vulgar, that it is not normally used in serious speech or writing:
I’m wiped out. (colloquial style)
I’m dead tired. (informal style)
I’m exhausted. (neutral/formal style)
I’m knackered. (slang = extremely tired, exhausted)