質問: I understand that しまう means unintended action, or the completion of an action. However, recently I came across this usage in the comment section on a website: ``` 遅くなってしまいすみません。 ``` While I understand this sentence perfectly, one part of it puzzles me greatly. So far, I've only seen ています, or てます where the い is omitted. Nonetheless, I've never see a case where ます is omitted. Here's how I'd parse this sentence: ``` 遅い=>遅く なる=>なって しまう=>しまい(ます) +すみません ``` After some homework done, I believe てしまい/しまって+すみません/ごめんなさい/etc. is a common usage. However, I still can't figure out how ます is missing here. Could it be that some other entirely different grammar is at play here? Please enlighten me. Thank you. (*Am I allowed to say thank you here?)
回答: > > 「遅{おそ}くなってしまいすみません。」 > > > is a perfectly grammatical and natural-sounding sentence. Nothing is omitted. In fact, it is ungrammatical to say: > > 「遅くなってしまい**ます**すみません。」 > > > 「しま**い**」 is the 連用形{れんようけい} ("continuative form") of the subsidiary verb 「しま**う**」. So, why is the 連用形 used? That is because the sentence does not end there. It still continues on to say 「すみません」. As you stated, there are a few ways to say "Excuse me for (verb phrase)." 1) 「Verb + Subsidiary Verb in 連用形 + すみません」 2)「Verb + Subsidiary Verb in te-form + すみません」 3) 「Verb in te-form + すみません」 There is no difference in meaning between those three, but 1) sounds the most formal, followed by 2) and 3) in that order. The actual sentences will be: 1) 「遅くなって**しまい**すみません。」 2) 「遅くなって**しまって**すみません。」 3) 「遅くなっ**て**すみません。」