Do Yyou Eever Ttake a Nnap?

I think it would be greant to take a 15 minute nap in days at work.

I think it would be granteat/amazing to take a 15 minute nap in days atwhen working.

But iIn Japan, I am warned to not take nap by my supervisor, even induring my lunch break time.

I think it would be greant to take 15 minute nap in days at works during work days.

But in Japan, I am warned to takefrom taking a nap by my supervisor even induring my lunch break times.

この文が難しかったですが、よくできています。

I think it would be grantnice to take a 15 minutes nap in days at work.

But in Japan, I am warnedwhen I was about to take a nap, I was warned by supervisor even induring the lunch break time.

Do You Ever Take a Naps?

Sometimes, I think it would be great to take a 15 minute nap during the day at work.

Combining this with the next sentence to create a full sentence, which is more standard in English writing. Here, "during the day" is a set phrase used in English.

I think it would be grant to take 15 minute nap in days at work.

But in Japan, I am warned againsto takeing naps by my supervisor even induring my lunch break time.

As written, the sentence suggests the opposite of your intended meaning - that your supervisor wants you to take naps. If you aren't supposed to do something, then we say "warned against" or "warned not to".

Do You Ever Take a Naps?

When asking questions about nouns like this it's usually the case we put it in the plural. This is because if we put the question into a singular, a person who does that thing multiple times may say no, when the intent is to ask if they do it at all.

Do you ever nap? ◎ <- nap here acts as a verb for the action of napping
Do you ever take a nap? △ <- nap is now a noun; this sounds very awkward
Do you ever take naps? ◎

("Do you ever take a nap?" ~= "Do you ever sleep?", which is a rhetorical question.)

I think it would be greant to take a 15 minute nap in days at work.

grant -> great: spelling

*a* 15 minute nap: missing article

in days at work -> at work: "at work" implies that you're spending the day there. also this is the more natural way to say it.

But in Japan, I am warned to take nap by supervisor even in lunch break time.[SEE THE FEEDBACK BELOW]

This sentence can be corrected in three ways, but first:

"But in Japan": This probably doesn't need to be here. Mentioning "but in Japan" implies that you're bringing the topic to now comparing countries' nap policies.

I'm given warnings by my supervisor when I take naps at lunch. <- this is correct but I doubt you're taking naps at lunch
My supervisor tells me to take naps, even at lunch time. <- this is also correct but I doubt supervisors are that nice.

These two corrections are based on context, so whichever fits, choose that.

I think it wshould be granted to take a 15 minute nap ion days at workdays.

But in Japan, I am warned to take nap by supervisor even inon a lunch break time.