I’ve seen this on the door tags of hotels, and was wondering what the grammatical construction is. “Molesten” doesn’t look like an infinitive, which I assume would end “-ar”, “-er”, or “-ir”; nor does it look like a second person plural or singular; and nor does it look like an imperative. Even though I don’t know much Spanish at all, I do know that in Indo-European languages generally imperative forms are close to the verb root, if not exactly that. Is the “-en” a suffix that references a potential object, like in “no tocarme” (don’t touch me)?
Molesten is third person plural imperative of molestar. The (understood) subject is Ustedes, the polite form of “you” (plural), which takes third person verb forms. “[You], do not disturb.”
This is in no way an answer to your question, but checkhttp://www.youtube.com/watch?v=HwqPeVkiDR4 that video out.
Pretty funny. 
To add up to Colibri’s answer, the “don’t touch me” sentence is not really correct. a better one would be “no me toques”, if you are talking with one person or “no me toqueis”, if you are talking with a bunch of rude guys (or gals).
The use of infinitives as imperatives is to certain degree extended in Spanish, but is not usually grammatically correct. You can check details of the officially correct use in here and here. To sum up, there are occasions where you can use infinitive, like talking about the past, but the imperative forms are for something. And, interestingly, infinitive can be used to ask the audience to do (or not) something, or in warning signs:
Do not smoke – No fumar
Wash by hand – Lavar a mano
You could see “no tocar” (in a museum setting), but “no tocarme” just doesn’t work. I’m sure there’s people who would use it, but it’s a very strange mixture of the most impersonal imperative-like form (the infinitive used as imperative) and that personal detail, “me.”
I’ve seen door signs which read “no molestar,” but again it sounds more impersonal; every time I’ve seen one of those, it was a non-Spanish-language-owned chain. “No molesten” says “I’m talking to you specifically, yes, you, person who is about to enter the room, yes, I know you’re the cleaning lady, I still want you to stay out.” In Mexico I saw “favor de no molestar,” which in Spain would have been “por favor, no molesten.”
(The only hotel where I’ve had to complain about cleaning personnel ignoring that sign was not in any Spanish-speaking country but I’m afraid the memory still raises my blood pressure)
“Molestar” is very obviously related to the English word “molest,” which can mean “disturb” but can also mean “touch a child in a way that’s totally inappropriate.” Is the same true of the Spanish verb?
Paula Poundstone used to have a bit where she expressed shock that, apparently, if you don’t put that sign up, then apparently, being molested is an option.
Nope… Molestar just means to bother. Hopefully Spanish speakers are teaching their kids to not say things like “that kid is molesting me” to a teacher or such!
So how would a Spanish-speaking kid allege that he/she were being molested, as in “touched inappropriately”?
The second meaning is quite recent in English, first attested in 1950. From here
Regarding Spanish, my Royal Academy of Spain Dictionary of the Spanish Language (2001) does not indicate any sexual meaning of molestar. Native speakers may be more aware if it has informally acquired such a meaning.
hmm… I’m not really sure! They could say “Me violo” if rape was involved, but I don’t know if there’s an equivalent word in Spanish to “molest”. “Me abuso” works as well.
The manhole covers of the town of Farmersville, Texas say "Manhole - Do not molest. I wouldn’t annoy a manhole, either.
Here is a picture of kind of what they look like… but this is in SF I think. Link.
It might be a Latin American thing, or just my not really knowing the language, but I have seen “No tocarlo” written to say “don’t touch (it)”. Of course the person writing it wasn’t necessarily fluent, either. I’m not sure about the “lo” part, either. He might have written “-la” or “-le”.
Obviously there’s a great deal of this in the United States, and I’ve long suspected that signage directed at Spanish-speaking employees is often way off base. For instance, outside one hotel I know there’s a sign, “Empleado Entrada”, which they must have literally translated from English. (This is a very old hotel by California standards, and they would probably be a little more accurate today).
I wonder why the third person plural infinitive is used, though? I should have been more specific in my OP; when I said it didn’t look like an infinitive to me, I meant a second person singular imperative. By sheer coincidence, the formal second-person imperative–both singular and plural–in German is the same as the third-person plural (and, as it happens, the infinitive). Not that I expect there to be any definitive answer as all languages have these odd little details.
I assume you mean imperative and not infinitive in the first two sentences.
I mentioned this in my first post. The understood subject is ustedes, the plural second person form. (In Spain it is the formal/polite form, while in Latin America it is used in both familiar and formal situations.) Usted is derived from vuestra merced, literally, “your mercy.” Although usted/ustedes are functionally second person, they take third person conjugations for historical reasons.
Vuestra is second-person plural, like vous in French. I’m not sure why just using the plural wasn’t formal enough in Spanish, as it was in French.
Is it wrong that I giggled slightly at the missing Ó?
For non-speakers: Me violo = I rape myself; me violó = he/she/it raped me.
Vuestra is neither plural nor a personal pronoun. It is the singular second person form of a possessive pronoun. Vos and vosotros are the other singular and plural second person personal pronouns. They’re used in some dialects of Spanish, but not used or heard in other areas unless it is in elementary school with a strict teacher teaching them all the conjugations (shudders remembering those times).
Vuestra is plural in the same sense that vosotros is plural. The fact that people were saying vuestra merced (your (plural) mercy) rather than tu merced (your (singular) mercy) suggests that they were using the second person plural as a sign of respect (this would be similar to the royal “we”). So vosotros could have become the formal “you” in Spanish, much as vous became the formal “you” in French (and you, the plural of thee, became the formal “you” in English).
Was I the only one who misread that for “Spanish Inquisition”?
Don’t make me go to the Real Academia Española on you.
Summary: Second person possessive pronoun, used when the following noun is singular (so a singular pronoun). Of course, the following noun, although singular, can be talking about more than one person.
So no, vuestra is not plural in the same sense as vosotros. The singular for vosotros is vos. The “tu” in “tu merced” is the possessive pronoun different from the “tú” second person personal pronoun. It’s not differentiated in pronunciation but it is differentiated gramatically by the accent mark.
And only some countries in Latin America (and I’m guessing some parts of Spain) use “vos/vosotros” in regular speech. The others just keep using the tu/usted forms. And I think there was a thread recently talking about regional differences in the use of those two pronouns.