Lesson 50: Doing the time with 後, 前/先, 時 (note さっき)
後・あと is a noun that means "after". X後で is a conjunction saying that something happens after X, and not necessarily immediately.
前・まえ is an antonym of 後 and means "before". 前 can both mean before in the spatial sense (i.e. in front of you) and in the time sense (i.e. the past). This is unintuitive because of the notion of "putting the past behind you", but if you remember that "People in front of you in line are Before Your Presence and Do Things Before You", you'll do fine.
The conjunction X前に means something happens before X does, not necessarily immediately. X前に can also just be a noun acting as the argument of a verb, in which case it means "in front of" in the spatial sense.
前 and 先 are almost synonyms.
先 is a noun meaning "before", "ahead", or "front end". Generally, when 先 is spatial, it means the front ("head") of something, or the direction it's headed, not the location immediately in front of it.
先 has two contradictory temporal uses.
Temporal use one means that something is ahead of something else, right now. A teacher is ahead of a student in life. It could also be something that happened just a moment ago.
Temporal use two means that something lies ahead, in the future. A career lies ahead of a student.
These uses seem contradictory, but they have the same fundamental idea. The contradiction only happens when you give the word "before" in some situations and "ahead" in others. English does the same thing and it's just as confusing.
This is a convenient way to remember that 先 doesn't arbitrarily change between being a word for temporal past and future. Instead, it depends on the situation or phrase, just like the english word "ahead".
The conjunction X先に works almost exactly the same way as X前に.
さっき is a version of 先 that is exclusively used as a "moment ago" time noun.
時 is a noun that means "time", but if you give it a relative clause, it can act like a conjunction.
また繋げたい時は言ってね
Tell me when you want to connect again, 'kay?