It's a nice sunny day and my leg is cramped. So rather than wasting it on the TV, I thought I use my spare time to talk about imperatives in Khmer.
In Khmer, there exist many particles used for asking question. There is no general one particle fits all, since the usage of particles conveys different imperative moods.
In formal language, a pre-clause particle "តើ/tae" is used to indicate a question. It is more than often dropped in spoken language, replaced by a dipping-rising intonation.
1.) ទេ/te : an affirmative particle, it conveys that the speaker is certain of the truth of what is being said and expect the answer to the question to be yes. It is mostly rhetorical.
Nieng skoal bong Phal te?
You know Mr.Phal (don't you)?
2.) ឬ/roe : an alternative particle, it is translatable to "or". This indicates that what is being asked has a wide possibility of answers.
Nieng skoal bong Phal roe?
You know Mr.Phal (or someone else)?
3.) ឬទេ/roe te : combined, it means "or not". It means the speaker does not anticipate an answer, but the question is limited to a yes/no respond.
Nieng skoal bong Phal roe te?
You know Mr.Phal (or don't you)?
These options can also be combined with words that indicate truth and actuality to make the question more certain.
For example, the word "មែន/mein" which roughly means "real" when combined with "te" means "right?". It still confirms the speaker's trust in the truth of the statement, but is not rhetorical like "te" alone.
4. ) ណា/naa : means "which/what". It asks a question to which the answer must be nominative.
Nieng Chan daer tiw bueng naa?
Chan walks to which lake?
5. ) ថ្វី-ថី/thvei-thei : means "why". It is unique that it is pre-clause, only logical since since it introduces a clause. It works the same way as its English counterpart, but it can never appear at the end of a clause.
Thvei ban nieng hoop num nuah?
Why did you eat that cake?
6.) អ្វី-អី-ស្អី/avei-ei-s'ei : means "what". It occurs with verbs, having the meaning as its english counterpart.
nieng kompung hoop avei
What are you eating?
Alas, there are much more ways to ask questions in Khmer, including rather complex constructions involving chaining together verbs.