Is the construction [されて終わりだ] grammatically correct?


I've found it in a parody [website](https://syosetu.org/novel/255759/2.html)
novel:

> のそのそしてる間に攻撃されて終わりだよ。

I tried to separate grammatically 攻撃されて終わりだ, but it's seems wrong to me:

**Passive voice in the て form + Aux-verb in the ます stem + だ Copulative Verb**

だ can't following a verb stem in order to spend the idea of informally (given
that the plain form already [does
it](https://japanese.stackexchange.com/questions/40582/can-you-
add-%E3%81%A7%E3%81%99-after-a-plain-form-of-a-verb)), and still the 終わり is
being used with the て form (like [aux-
verb](https://japanesetest4you.com/flashcard/learn-
jlpt-n4-grammar-%E3%81%A6%E3%81%97%E3%81%BE%E3%81%86-te-shimau/), if it was
the case). I've seen that, in the most of the time, it is used with the [ます
stem](https://nihongokyoshi-net.com/2019/04/02/jlptn4-grammar-owaru/).

Is it a right interpretation did I do?

**NOTE** : I saw it too in a
[news](https://hochi.news/articles/20210505-OHT1T50054.html) in the following
phrase:

「きょうは独り言を言 **って終わりだ** 」。




(Edit: I noticed I forgot to explicitly answer the main question. **Yes, as
far as I can tell it is grammatically correct.** )

終わり is the so called 連用形（れんようけい）"connective form" of 終わる. This form does
indeed serve as ます-stem, but **it can also serve as a nominalization of the
verb**. In this case 終わり means "(the) end".

In fact, the 連用形 ("ます-stem") can be used to create nouns for most verbs. The
resulting noun will have the meaning of "the act of ~ing", but it can often
carry additional meanings as well:

切る "to cut" -> 切り "cutting (the action)", or more frequently: "cut (the
result), "limit" (in an expansion of the original sense) etc.

The て-form can be used to connect the previous phrase with a following
auxiliary verb, but it can also connect the previous phrase with a following
phrase (and not neccessarily an auxiliary). This connection can be a temporal
one / succession (ＡしてＢ: "Do A and then B"), or as it seems to be the case in
your question, a rather conditional one (攻撃されて終わりだ: "If you get attacked, it's
the end (= it's over)"). This conditional sense resembles the usage of the
auxiliaries -たら or -ぇば.

I'm lacking the context but I'd guess an appropriate translation would be
something like: **" If we get attacked while we're slugging around, we're done
for!"**

(ps This is my very first time posting on Stack Exchange so I hope I didn't
mess anything up. Feel free to provide feedback, edit or correct me if
neccessary.)




(Edit: I noticed I forgot to explicitly answer the main question. **Yes, as
far as I can tell it is grammatically correct.** )

終わり is the so called 連用形（れんようけい）"connective form" of 終わる. This form does
indeed serve as ます-stem, but **it can also serve as a nominalization of the
verb**. In this case 終わり means "(the) end".

In fact, the 連用形 ("ます-stem") can be used to create nouns for most verbs. The
resulting noun will have the meaning of "the act of ~ing", but it can often
carry additional meanings as well:

切る "to cut" -> 切り "cutting (the action)", or more frequently: "cut (the
result), "limit" (in an expansion of the original sense) etc.

The て-form can be used to connect the previous phrase with a following
auxiliary verb, but it can also connect the previous phrase with a following
phrase (and not neccessarily an auxiliary). This connection can be a temporal
one / succession (ＡしてＢ: "Do A and then B"), or as it seems to be the case in
your question, a rather conditional one (攻撃されて終わりだ: "If you get attacked, it's
the end (= it's over)"). This conditional sense resembles the usage of the
auxiliaries -たら or -ぇば.

I'm lacking the context but I'd guess an appropriate translation would be
something like: **" If we get attacked while we're slugging around, we're done
for!"**

(ps This is my very first time posting on Stack Exchange so I hope I didn't
mess anything up. Feel free to provide feedback, edit or correct me if
neccessary.)

