This tag is used on some sentences that are in the Proofread English Sentences list that is also known as List 907.
https://tatoeba.org/en/sentences_lists/show/907

It's now marked as a Berber sentence.

in addition to that, I found that the Chinese period (。) and Chinese semi-comma (、) is considered a word, they add up the word count and can be searched, but the Chinese question mark (？) and most other punctuations are not considered a word and cannot be searched.

You could try these approaches to find sentences with a high-probability of being English questions.

^who|^what|^where|^when|^why|^how
Sentences beginning with these question words

^Is|^Are|^Was|^Were|^Do|^Does|^Did|^Can|^Could|^Will|^Would
Sentences beginning with these question words

Here is a link that will give you a random selection with both of the above combined.
Results limited to sentences with audio and 3 or more words.
After trying this, you can edit the search criteria.

https://tatoeba.org/en/sentence...rd_count_min=3

I removed the &rand_seed, so clicking the link again will give different results.

> Is it really true that this is impossible with the current search function?

Yes, and there are at least three reasons:

(1) The question mark is already being used for a specific purpose, and though theoretically it could be escaped, the search engine we use (which was not developed by us) doesn't allow this.

(2) When the search engine indexes words (stores them in a form that makes them easy to look up and compare), it throws away punctuation symbols. Again, I don't think this is something we could change.

(3) Searches can only be performed at the word level, at the stem level (for languages that support stemming, which allows, for instance, a match between "live" and "living"), or at the level of sequences of three or more letters. A question mark doesn't match any of these levels.

The combination of these three factors makes it unlikely that your request would be implemented, but I suppose it's always possible.

CK's suggestion that you search for sentences beginning with question words is probably the best you can do if you want to rely on the search provided on the Tatoeba site. Another option is for you to download a full set of sentences (for instance, all the sentences in English, or all the sentences in English with translations in French) from the Downloads page ( https://tatoeba.org/en/downloads ). Then you can search for question marks with a text editor or with a spreadsheet application (like Libre Office or Excel).