Merci Paul, I'm glad I got the general meaning.
No problem. Glad to help. It's good practice.
３機とも戦闘不能になった時点でOnce all three machines have been disabled (for combat), the sublieutenant loses.
３機とも means 'all three machines'.
戦闘不能になる means 'become disabled for combat'.
～時点で means 'once~' or 'at the point in time in which~'.
What is the function of で there? In Tae Kim's guide it says: It may help to think of 「で」 as meaning "by way of". This way, the same meaning will kind of translate into what the sentence means. The examples will then read: "Saw by way of movie theater", "Go home by way of bus", and "Ate lunch by way of restaurant."
The thing is I don't really see how it would work with 時点 here.
で serves a lot of functions. I don't think Tae Kim's definition covers all of them. The way I see it, で is best thought of as being used to mark phrases that indicate not only the means, but also the setting or circumstances for some other action or event. For example:
寿司を 食べた。 (はしで すしを たべた。)
'I ate sushi using
映画を 見た。 (えいがかんで えいがを みた。)
'I saw a movie at
a movie theater.'
3) 彼は 承知の上で
悪いことを やった らしい。
'It seems he did it knowing
it was wrong.'
In (1), chopsticks serve as the means for eating sushi. In (2), the movie theater is the setting for the action of watching the movie. In (3), 彼 did bad things with the setting being that he knew that they were bad.
Anyway, in the dialogue from the game, で marks 時点, which is a moment in time; that moment is the setting in which the event of the sublieutenant losing takes place.
What is the function of に there? There are so many functions for the に particle that I often find myself unsure as to how is meant to be used.
Are there any ways or tips to quickly figure out what is the usage of に in a sentence?
EDIT: thanks Ryusei.
Ryusei said pretty much everything that needs to be said for に, but I'll just add that に contrasts with で in a very crucial way: で indicates a span
; に indicates a point
. Check out these two sentences, which sum up the core difference in usage between the two particles:
電車が ここに 着く。
'A train will arrive here at
(i.e. the point at which it becomes) 1:00.'
日本語を 勉強 する。
'I'll study Japanese for
(i.e. within the span of) one hour.'