No, the phrase "top of the line" is not hyphenated.
No, the phrase "thank you note" is typically not hyphenated when used in a sentence.
Yes, back-to-school is hyphenated when used as an adjective phrase before a noun, such as "back-to-school shopping."
Yes, "limited-time" is hyphenated when used as an adjective phrase to describe something that is only available for a short period.
Yes, "year after year" should be hyphenated when used as a compound adjective before a noun (e.g., year-after-year performance). However, it is not hyphenated when used as an adverbial phrase (e.g., they met year after year).
"On top of the world" is a prepositional phrase. Prepositional phrases consist of a preposition (in this case, "on") followed by a noun phrase (in this case, "top of the world"). They function as adjectives or adverbs in a sentence.
Yes, you use hyphens for the phrase "top-of-the-line." It is a compound adjective that contains a preposition, so it is hyphenated.
It should be hyphenated.
Yes, end-product is hyphenated. It is a noun and treated as one word which is hyphenated.
No.
Probably not.
No, the phrase "thank you note" is typically not hyphenated when used in a sentence.
The noun phrase 'four week vacation' does not need to be hyphenated.
Yes and no. The out-of-plumb wall should be hyphenated while the wall was out of plumb should not.
Yes, one-on-one is hyphenated. I don't know why, exactly. It just is.
No
Yes, back-to-school is hyphenated when used as an adjective phrase before a noun, such as "back-to-school shopping."
Point of sale is a business term used to describe when the retail transaction is complete. The phrase "point of sale" is not hyphenated.