Hi, Basically, your two columns mark out the phrases into informal and formal, so I think you are already pretty confident about when you would use each phrase. Personally, I would be wary of using informal phrases in formal documents, although I would use them freely in an email. Informal Formal bring up refer to keep from prevent keep up continue, go on cut down on reduce, (dwindle) get into enter bottom line what matters most I have made an exception of dwindle, because this doesn't really mean the same as 'cut down on'.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.