Adverb modifying a noun?

Question

I stumbled upon the following dialogue line in a game:

おや、連絡かね。手早く確認が仕事の基本だよ

What puzzles me is the adverbial form of 手早い being used, despite there being no verb (or any other part of speech it could modify) I could discern in the sentence. It would make the most sense to me that the word it modifies should be 確認, but in that case I would rather expect something like "手早く確認するのが…" or maybe "手早い確認が…", if these are correct ways to phrase it. Is it really 確認 that's being modified and what is the grammar at play here?

Answer 1

This 確認 is not a noun but a verb with する(の) omitted. Here, 手早く確認 is working as something like a slogan that could have been in quotes. So you can read it like:

「手早く確認！」が仕事の基本だよ。
"Check it right away!" is the basic part of working.

Note that a suru-verb can work as a short imperative without する or しろ (e.g., "起立!" = "Stand up!", "整列!" = "Fall in!"). You can even use しろ explicitly and say 手早く確認しろが仕事の基本だよ. This can safely be parsed without visible quotation marks.

手早く確認するのが仕事の基本だよ and 手早い確認が仕事の基本だよ are also perfectly correct, but the original sentence would sound a little more impressive because the 手早く確認 part sounds like it's urging you to take an action.