It should be hyphenated.
It should be hyphenated if used as a noun clause, but not if used as an adjective
It should be hyphenated.
Yes, "half-page ad" should be hyphenated to show that "half" and "page" are acting together as a compound adjective to describe "ad."
Self-made should be hyphenated.
Pre construction - two words not hyphenated.
Underdeveloped should be written as one word, not two words or hyphenated. I hope this answered your question. :)
it should be hyphenated: close-out
Roller-skate, as a verb, should be hyphenated. Roller skate, as a noun, is not.
Fine-tune is an 8 letter hyphenated word. High-tech, half-mast, half-moon are additional hyphenated words.
The use of a hyphen is often in question when referring to two words. If one is using "half day" to modify another noun, then proceed with using the hyphen. For example, a "half-day holiday", and "I took half a day off".
Yes it should be hyphenated.