The pattern ～てくる is also really useful way to express a change in state. I remember it being a confusing pattern when I first started studying Japanese, but I solved that problem by using it constantly (regardless of whether or not it was appropriate) because, let’s face it, shit be changing, yo. (Cue Tupac track.) Gradually I’ve narrowed down the appropriate usage conditions.
Here’s a quick example sentence: この2ヶ月間仕事が忙しくて大変だったけど、やっと落ち着いてきた。
The first clause sets the scene – work was busy and it sucked. But (there’s the fulcrum for the change) things have settled down (or so he thinks). The second clause shows how things have changed from the first clause. They have gone from an 落ち着いていない condition to an 落ち着いている condition. The きた, I feel, helps emphasize this transformation and the やっと impresses exactly how long the subject was waiting for the きた to くる so he could キター！
So the next question is what’s the difference between ～た and ～てきた? It’s pretty subtle. Another example. I got a birthday package from a friend in the US the other day. If my friend spoke Japanese I could say that it got here with a simple 荷物が届きましたよ. Just the basic way to say that the package was delivered. I could also say 届いてきたよ, which feels more urgent – as if my friend or I were awaiting the arrival of the package slightly more desperately. Maybe the package was delayed? Maybe there was a kitten inside?! Or maybe we were just waiting to compare the USPS with Japan Post. (Japan Post wins.) As in the example yesterday, the きた・くる seems to address a sort of mutual understanding that exists whereas the plain form of the verb is best for communicating brand new information.
〜なってきた・くる is another pattern that you can use to express how something changes. An example: 寒くなってきた. Like Monday, the timeframe feels more specific, as in 最近 or 今日 or 今週. And once it’s cold enough, (you can use Monday’s pattern to say…) 雪が降ってくる.
In some of these I think there is some potential ambiguity with what I guess is called the “inceptive” usage of “-te kuru”, i.e. “it’s starting to get cold”, “work’s finally starting to settle down.” This paper I found seems like a pretty good “intro to kuru” too: http://edocs.lib.sfu.ca/projects/NWLC2002/NWLC2002_Proceedings_Yin.pdf
There’s also a parallel in English, “come” with an infinitive. This certainly doesn’t always work, but in this case, the Japanese and English grammar is rather close. So, 「だんだん日本人の精神がわかってきた」 (Dandan Nihonjin no seishin ga wakatte kita) can be translated, “Gradually, I have come to understand the mentality of Japanese people.”
The way to summarize it which covers all the bases most completely, I think, is to say that it signifies a process with emphasis on what has been or will be completed. Note that the process may or may not be completed YET. So, in the example sentence I suggested above, the speaker may continue to learn more about the Japanese mentality, but the emphasis is on what has already been completed. The same person might say, 「そのうち君もわかってくるよ」(Sono uchi kimi mo wakatte iku), which means, “Soon you will [start to/come to/etc] understand it, too.” This is future, but denotes that a process will gradually come to fruition.
Similarly, ～ていく (-te iku) is almost the same, but with emphasis on the beginning of the process. So, 「だんだん社会が変わっていく」 (Dandan shakai ga kawatte iku) means, “Society will gradually begin to change.” In certain cases this can be translated as “go on to” (like, 「あのときから親しくなっていった」(Ano toki kara shitashiku natte itta.) “After that, (someone) went on to become more intimate/closer.”), but this is a bit less directly equivalent to the Japanese phrase in my mind. The important thing is to understand that both emphasize a process, but they signify opposite ends of the process.
Because of this, incidentally, if you want to emphasize the process, and especially the completion of the process, ～てくる is useful. And the situation Daniel proposed with the mail is one such situation. So that’s a special use of this pattern, but it fits with the overall sense.
I have very little knowledge of linguistics, but I’m not sure I like this “inceptive” mumbo jumbo – it feels like the category is kind of forced on the Japanese by the English chosen as the translation. She uses two examples: 雨が降ってきた and 火が消えてきた. The rain one works better, although I think the Japanese emphasizes the “end of the not-raining” just as much as the “beginning of the rain”.
The flame one seems really weird to me in the English. A flame “starting/started” to go out only works in English if it’s a really big flame. Would 火が消えてきた be used for a match? And if so, wouldn’t the flame already be out at that point that phrase was used? Hmm…I guess if the match got fluttery there for a second that phrase feels right.
I like DBP’s explanation because it emphasizes that interval between states. And because something has been completed, some change has taken or will take place, maybe that’s why I feel like more qualifiers, either explicit or implicit, are required.
I guess basically I feel like “inceptive” and “reaching a state” are more closely linked than in the diagram she has at the end. It just feels like the “point of inception” is not as well-defined for the examples used in “reaching a state.”
Yeah, I don’t really have the chops anymore to critique the diagrams in detail (like I ever did, ha). But I like the attempt to catalog all varieties of usage. Also, the “火が消えてきた” example works for me, although maybe in translation you wouldn’t say “started to go out” because English doesn’t work that way. “Eventually the flames began to die down. That was when we realized that we’d set fire to the wrong car.”