Use a dime a dozen to say that there are many things like it and they are easy to find: 'Cheap phone cases are a dime a dozen near the station.' It does not mean that each item costs ten cents. The phrase is informal and can suggest that the thing has little distinction in that context.
Use a person of few words for someone who does not speak much or tends to give short answers. You can say, 'Mina is a person of few words, but she listens closely.' The traditional phrase a man of few words is used for a man; use a woman of few words for a woman, or a person of few words when you want a gender-inclusive description.
A shot in the dark is a guess with little evidence or information behind it. Use the idiom for an uncertain attempt, not for a fact that has been checked.
Write a while after a preposition, as in for a while or in a while, and in a while ago or a while back. Write awhile when it directly follows and modifies a verb, as in wait awhile.
Use an abstract noun when you need to name an idea, feeling, quality, action, or state. In Her courage impressed the audience, courage names a quality rather than a person or object.
Every acronym is an abbreviation, but not every abbreviation is an acronym. An acronym comes from initial letters and is said as one word; a general abbreviation may simply shorten a word, and an initialism is said letter by letter.
In active voice, the subject does the action: The team finished the report. In passive voice, the subject receives the action: The report was finished by the team.
Treat the adjective and preposition as one unit: good at, interested in, afraid of, responsible for, and proud of. After the preposition, use a noun phrase, a pronoun, or an -ing form for an activity.
Put a single describing adjective before the noun or after a linking verb such as be. With several adjectives, start with an opinion or size, then add details such as age, colour, origin, material, and purpose.