What is ながらだと? How is different from ながら?


目を逸らしながらだと撫でられますよ

Tl: While avoiding his eyes, you can pet him.

But what is the だと in ながらだと?




だと means "if (it's)", "if (we use)", "if (you mean)", etc. It's a relatively
informal expression. Note that this と is not the quotative particle but the と
meaning "if/when". See: [Function of
"だと"](https://japanese.stackexchange.com/q/52928/5010)

だと mainly takes a noun:

  * 彼だと彼女に勝てないだろう。  
If it's him, he wouldn't be able to beat her.

  * 明日だと10時が空いています。  
(If you like) tomorrow, 10:00 is available.

But it can also take adverbial expressions such as ゆっくり, 赤く, 急いで, いっしょに, ～から,
and ～ながら. This is a convenient way of applying the meaning of "if" without
explicitly saying the corresponding verb:

  * 白く塗るのはいいが、赤く **だと** 目立ってしまう。  
= 白く塗るのはいいが、赤く塗ると目立ってしまう。  
Painting it white is fine, but if you paint it red, it would stand out.

  * ゆっくり **だと** 間に合いませんよ。  
= ゆっくりやると間に合いませんよ。  
If you do it slowly, you will not make it in time.

  * 明日を待ってから **だと** 遅すぎます。  
= 明日を待ってから出発すると遅すぎます。  
If we depart after waiting for tomorrow, it would be too late.

  * 目を逸らしながら **だと** 撫でられますよ。  
= 目をそらしながら撫でると撫でられますよ。  
You can pet it if you do it while looking away from it.

