How to ask a question?

What is being omitted, especially on message boards, is the question: "Does anyone know.." For instance:

"Does anyone know how to get from the airport to downtown?"

It's somewhat similar to asking people at a party:

"Drinks?"

At a party, drinks are expected. On message boards, questions are equally expected.

Ah, good point about "Does anyone know.. ?". However, in practice, it seems that many people online frequently omit the question mark from their topic titles, leading to the reader's confusion: as previously mentioned, in the absence of proper punctuation and without any 'helper words', the statement's meaning becomes unclear.

You said: "on message boards, questions are equally expected". Not necessarily. Even on a board that typically contains only questions, an informative "How to.." guide may be posted so that others in the future do not have to ask the same question. As many messageboards contain a mix of questions and informative posts, it would be wrong to assume that the absence of a question mark at the end of a "how to.." topic title indicates a question within.

Regardless, it seems that due to it's frequent use online, many people - both those who are learning English as a 2nd language as well as native-English speakers - are now using "How to.. ?"(with or without a question mark!) in their every-day speech or writing. Someone stopped me on the street the other day and said: "Hi - excuse me. How to get to the library?"

English is a funny language. Where the simple question, "Drinks?" is an acceptable short-cut, "How to get to the library?" really does need a "Could you tell me.." in front of it. A "please" would be nice, too.

^ Oops - typo... 3rd paragraph should be "due to *its* frequent use".

i have frequently seen "how to" at the beginning of instructions. I have never seen it at the beginning of a question except when spoken by a foreigner who barely speaks English.

Then you need to get out more (on the Web, too).
Hey look, you can play the "Question or Instruction Game" until your heart's content:

http://groups.google.ca/groups?&q=%22how%20to

ex: "How to get from the airport to downtown?"

ex: "How to remove blood stains from clothing?"

I don't believe that too many people would ask in this manner; however, I could see those (as statements, not questions) used as titles of instructional leaflets or by a child for a class project.

Wow...I guess I should read more before I write. Thanks, Anonymous.

In instructions, there is no question mark, as it's a statement:

"How to operate this machine" means "This is how to operate this machine" or "Here's who to operate this machine".

But in captions in forums and the like, I see it as highly informal yet acceptable shorthand. Elsewhere I would object to its use. It should never be used in "real" writing.

Also consider, a title, especially one in a forum or bbs, etc., is generally not a full sentence, nor is it supposed to be. A sentence fragment is perfectly acceptable and is commonly used. (same Anonymous as above)

I believe you are grouping the question word with the first part of the infinitive, thinking that this creates a new form of question word, i.e. "How to" something. What you are in fact doing is something that a lot of native English speakers do all the time which is called "splitting the infinitive". The "to" in this question actually belongs to the verb infinitive (or to put it more clearly, the dictionary form of the verb -- "to eat" or "to operate"). As other writers have pointed out and perhaps what you might not be hearing properly in conversations is that the proper way to ask a question is "How do I operate...?" The answer when stated as a response actually creates a noun out of the verb infinitive "to do" or "to operate" (this infinitive noun phrase is called an infinitive phrase).

When reading "How to" articles, the titles of the articles aren't true sentences but sentence fragments. As Chris pointed out earlier, the proper way to answer a question such as "How to do something?" would be: "This is how to operate this machine." In this case, "This" would be the subject and "how to operate this machine" would be an infinitive noun phrase.

English is very difficult... I have to admit I didn't totally understand its grammar until I started learning other foreign languages with much more logical grammar syntaxes.

The standard structure of a Wh- question is...
[“Wh-” Question Word/Phrase] + [Auxiliary Verb] + [Subject] + [Main Verb] + [Object or Other Information] + ?
but there are some questions that don't follow this structure such as "What are the characteristics of a leader?"
What is the exception here and what structure does this follow?