Let's do lunch some time next week.
The sentence is not, because an idiom is usually a phrase. The idiom is "do lunch," which means to have lunch together, usually while discussing business.
My Favorite IDIOM Is, When Pigs Fly.
Idiom
The prepositional phrase in the sentence is "for lunch."
"The idiom 'that just kills' is hardly appropriate at a funeral."
That phrase must be an idiom, because I can't understand what it means."It's raining cats and dogs" is an idiom for "it's raining really hard.""I am learning about idioms in English class."Timmy was the apple of my eye".This sentence is an example of an idiom.
An idiom usually is a sentence, or part of one. It certainly can be used as part of a sentence. The way to tell if it's an idiom is if it makes sense the way it's literally written.
That IS a sentence.
"Throw the book at him" IS a sentence.
yes
Yes, this is a run-on sentence, because it contains two independent clauses (each can stand alone as a sentence) that are not separated by any punctuation or conjunction.The following are examples of how to correct this error:Before lunch you played volleyball. After lunch you played again.Before lunch you played volleyball; after lunch you played again.Before lunch you played volleyball, and after lunch you played again.
"Hit the books" is a sentence.