Idioms are phrases or expressions whose meaning should not be taken literally. I cannot be understood by simply knowing and putting together the ordinary meanings of the separ…ate words in it. Examples: Contracts, agreements, and memos should be put into Black and White. (into writing) I burned the midnight oil whenever there's a test. (study thoroughly) (MORE)
1. "Idiom" begins with a vowel, so you use the word "AN" in front of it..
2. You cannot "do" one because it is a noun and not a verb..
The question is unclear. Please rephra…se it so that your meaning is more understandable.. (MORE)