"Off and on" means periodically, sporadically, or randomly.
For example, if someone asks "Is it raining?" You might answer "Off and on." if it was raining for awhile and then stops for awhile.
Or if someone asks if you're working on the project, you could say "Off and on" if you're also doing other things.
Show off
the idiom of really upset is "pissed off"
Madagascar is not an idiom, it is an island off the coast of Africa.
Can you figure out the meaning literally? Then it's not an idiom. The person is saying that they didn't want to use force to move someone away from something.
An idiom misuse is to use and idiom in a wrong way that doesn't make sense.
"Chip off the old block" IS an idiom! It means that the child is just like the parent.
An idiom is something that does not mean what the phrase says literally, so yes. You can't actually laugh your head off.
Dozing off ; Being distracted ; Not paying attention
The idiom will u please get off my back means stop bugging me or leave me alone
I cannot find an idiom that starts off "she cried tears." When you cry, you cry tears, so that would not be a good idiom anyway.
It is an idiom, because it does not use the term "like" or "as".
"Write it off" means to dismiss something.