Can 気づく be used with quotation と? As in this example: > I think that the beginning says: "As for Mr. Lewis's Japanese, even Prof. Ōta..." And then the end is: "...[his Japanese] is so good to the extent that he [Prof.] didn't realise." But did he not realise "if he was a foreigner", or that "he was a foreigner" just enclosed with the particle?

> Can {} ("to realize") be used with the quotative ?

Yes, it definitely can.

Why so? Because in Japanese, the quotative is used with far more verbs than English-speakers might associate with upon hearing/seeing the word " ** _quotative_** ".

Those verbs include:

{} "to say"

{} "to speak"

{} "to hear"

{} "to write"

{} "to think"

{} "to feel"

{} "to teach"

{} "to notice", "to realize"

There are **_many_** more. Crazy, isn't it?

> But did he not realise "if he was a foreigner", or that "he was a foreigner" just enclosed with the particle?

The latter. My TL would be:

> "Lewis's Japanese was excellent to the extent that did not even realize that he was a foreigner."

If this helps, . If imaginary quotation marks seemed to make sense for the word/phrase right in front of , you could be sure that it is the quotative .

In other words, thought that Lewis was a native Japanese speaker.