brilliant
No, building is not a compound word.
One is booster club, an open compound word.
Yes, though it is often hyphenated as man-made, which is a type of compound word.
No
rainbowraincoatrainfallrainmakerrainshowerrainstormrainwaterrainware
No, "suddenly" is not a compound word. It is an adverb formed from the adjective "sudden."
Apyphony.
no idea
Good morning is not a compound word.
"Outburst" is a compound word that ends in "burst." It refers to a sudden release of strong emotion or sound.
Good morning is not a compound word.
All of a sudden a wild badger attacked me.
Yes, mockingbird is a compound word.
No, seeing as a compound word must be one word, such as teacup or watermelon.
Yes, idea is a word. You had a good idea to come and ask that question here.
They had a good idea for the project.
The idea of democracy is great. But it doesn't work.