Learn Russian: Кто это?

In Russian, the verb "to be" (am, is, are) is almost always dropped in the present tense. You simply put the words together, so "Who is this?" translates literally to just "Who this?".

Since we are asking about a person, shouldn't we use a subject pronoun like он (he) or она (she) instead of это?

You can ask Кто он? (Who is he?) or Кто она? (Who is she?) if you are already talking about a specific man or woman. However, Кто это? is the standard, most common way to ask "Who is this?" when you are first pointing someone out, and it works perfectly for any gender.

Do I actually pronounce the "k" and "t" together in Кто?

Yes! Unlike English, which has silent letters in words like "know" or "knight," Russian pronounces both consonants here. Just make a quick, crisp "k" sound immediately followed by "t".

Would I also use Кто это? to ask about a thing or an object?

No, кто strictly means "who" and is only used for living things like people and animals. If you want to ask about a lifeless object, you must use the word for "what", which is что, to say Что это? (What is this?).