?

? U+003F, ? QUESTION MARK ← > [U+003E] Basic Latin @ → [U+0040]

There are two primary theories of the origin of the question mark. One is that ⟨?⟩ descends from the punctus interrogativus ⟨⹔⟩, which instructed the reader (or singer) to raise the pitch of their voice while coming to a stop.

Another theory is that it derives from ${\displaystyle {\overset {Q}{o}}}$, an abbreviation of Latin quaestio (“question”), placed at the end of a question to mark it as such, and analogous to the derivation of ⟨!⟩.^[1]

There are no documented intermediary forms to support one theory over the other.

? (English name question mark)

1. Used in various left-to-right scripts, including notably the Latin script, to mark the preceding sentence as a question.
2. (comics, Internet slang) Used by itself to convey that the speaker is confused.

   Character #1: "I have no time to explain! Have you seen a Big Bad Wolf blowing down various houses?"

   Character #2: "?"

3. (linguistics) Marks the following word or phrase as questionable for a grammatical or semantic-pragmatic reason.
   • 2006, Renaat Declerck, Susan Reed, Bert Cappelle, “The Grammar of the English Verb Phrase”, in The Grammar of the English Tense System, volume 1 (in English), →ISBN, page 6:

     A superscript question mark will be used similarly to indicate that a sentence or constituent is questionable for a grammatical or semantic-pragmatic reason. A double superscript question mark indicates an even higher degree of questionability.
     I have never { worked / ^?been working } on a dissertation
     This time tomorrow I { will / ^??am going to } be driving to London.

• For the reversed question mark used in some right-to-left scripts, such as the Arabic script, see ؟.

?

1. A placeholder for an unknown word, phrase, text, or numerical value.
   • 2009, Terry Stickels, Math Puzzles and Brainteasers, Grades 3-5: Over 300 Puzzles that Teach Math and Problem-Solving Skills (in English), John Wiley & Sons, →ISBN, page 6:

     What is the next number in the sequence below?
     1    4    9    16    25    36     ? 

2. (chess) Indicator of a bad move.
3. (programming) A wildcard for one character in query language.
4. (programming) The ternary operator in some programming languages.
5. (regular expressions) Detects zero or one occurrences of the preceding element.

   The string colou?r matches both "color" and "colour".

6. (networking) In a URL, begins a query string (a series of data formatted as field-value pairs).

   https://en.wiktionary.org/w/index.php?title=Wiktionary:Word_of_the_day&action=view

• Its English name is variously question mark, interrogation mark, interrogation point, eroteme.

For quotations using this term, see Citations:?.

• (?)

• ¿ ? (Spanish)
• ??
• ?!
• !
• !?
• ‽
• !!
• ؟ (Arabic/Persian)
• ？ (CJK)
• ; (Greek)
• ՞ (^?) (Armenian)
• ⸮

Punctuation

? (plural ?s)

1. (text messaging) A question.

   i hav a ? 4 u (I have a question for you)

2. objects seen/shaped as the question mark

   a ? block (a question-mark block)

?

1. Used in ¿ ?
2. (nonstandard) Marks a preceding passage as a question, without the starting ¿, as in English and other languages

   Cómo estás? ― How are you?

• As SMS messaging and other forms of electronic communication have become more common, some Spanish-speakers use only ? for questions and ! for exclamations, leaving out the initial typographical mark. This is considered non-standard usage.

• ¿ ?
• ¡ !