Are 这是哪 and 这是在哪 different questions?

Question

On WeChat, I noticed one of my friends wrote:

这是哪？
_{zhèshìnǎ？}

Meaning "where is this?" This surprises me as I would have expected

这是在哪？
_{zhèshìzàinǎ？}

Both of these are easily found used online. I'm wondering if they're the same.

Question: Are 这是哪 and 这是在哪 different questions?

There's also other variations I found online:

这是（在）哪里？
这是（在）哪儿？
这里是（在）哪里？
这里是（在）哪儿？

And it's quite possible every combination of these (and maybe more) has the same meaning too.

Answer 1

The key to differentiate between 这是哪（儿） and 这是在哪（儿） is to understand the different usages of the character '这'.

这 have several meanings, I just listed two of them relevant to this topic:

1. referring to a person, thing, or place, like the word 'this' in English. For example, 这是我家。 means This is my home.
2. used to emphasize 现在, like the word 'now' in English. For example, 我这就来. means I am coming now.

这是哪？, 这（subject）+ 是（verb）+ 哪（target）, simply means "where is it?".

这是在哪？, 这（intensifier like an adverb in English, modifying 是）+ 是（verb）+ 哪（target）, implies 现在是在哪, apparently the sentence omits a subject "我们". The complete sentence should be "我们这是在哪", and the equivalent sentence in English is "where are we now?"

In this case, I gather your friend asked this question in your moments of WeChat, where you might post some scenery photos. So, 这是哪("where is it") is more accurate here.

Some explanations on these sentences you quoted above:

这是（在）哪里？: This is the same as "这是（在）哪"，as talked above.

这是（在）哪儿？: This is the same as "这是（在）哪"，as talked above.

这里是（在）哪里？: 这里是哪里 == 这是哪里==这是哪（儿）， 这里是在哪里 is unnatural and it should be either 这里是哪里 or 这是在哪里. The difference has already been talked about.

这里是（在）哪儿？: 这里是哪儿==这是哪儿==这是哪里， 这里是在哪儿==这里是在哪里， which is unnatural and should be either 这里是哪儿 or 这是在哪儿. The difference has already been talked about.

PS: In this case, 这是在哪 could be short for 这是在哪里拍摄的 or 这是在哪里照的. But people usually won't apply the omission(just use the full version), because the short version "这是在哪" could mean differently as mentioned above. So, 这是哪 is better than 这是在哪，because 这是在哪 creates a bit ambiguity. It might be ok to put 这是在哪 here, but people need to think a bit to interpret what you mean is 这是在哪里拍摄的 (where had the photo been taken?). In practice, people really don't care that much. It might just be a little nitpick to determine whether 这是哪 or 这是在哪 should be used in this case. But natives would use "这是哪（儿）", "这是在哪里拍的？", "这是在哪里照的？" etc...

Answer 2

• "这是哪？" short for "这是哪里？"; It means "where is this place/ what place it is?" (you want to know the name of a place)

Example:

A and B are at a park,

A asks B: "这是哪(里)?" - "where is this place?"

B answers: "这是佛光山公园" - "This is Buddha Light Mountain Park"

It would be easier to understand if you say "这是什么地方" instead of "这是哪？"

• "这是在哪？" short for "这是在哪里？" It means "where it is at?" (you want to know where an object is located or where an event took place)

Example:

A pointing at a poster and asks B

A: "佛光山公园？ 这是在哪？" - "Buddha Light Mountain Park? Where is it located?"

B: "佛光山公园当然在佛光山" - "Buddha Light Mountain Park is in Buddha Light Mountain of course"

A: "不，我的意思是佛光山公园在哪个城市" - "No, I meant Buddha Light Mountain Park is in which city"

~

"曹操刚跟呂布战斗？这是在哪(里发生的)？" - "Cao Cao just fought with Lu Bu? Where was it (took place)?"

Answer 3

这是哪: Where is this place, The answer can also be a specific location or not a specific location. 这是在哪: Where is it, the answer is a specific location.

Answer 4

这是哪?

A declarative form might be: 这是公园.

这是在哪?

A declarative form might be: 在公园.

e.g.

A: (show a photo)

B: 这是在哪(拍的照片)?

The declarative form can be "这是我在公园拍的照片"

哪里 = 哪

这是哪里 = 这是哪

哪儿 is 儿化音