Before attempting to pronounce the word yourself, listen carefully to how the instructor pronounces "kto" in the video. Don't be misled by the phonetic transcription as "ka-toh." This is given merely to distinguish the "k" and "t" as distinct sounds; neither letter is silent. When the word is spoken at normal speed, it becomes a single syllable.

Notice that when Alena says the word quickly, the "k" is still audible. Listen to the example in the video before trying to pronounce the word yourself.

The "o" sound in "kto" is shorter than some English speakers may try to pronounce it. Contrast the clipped "o" in Alena's pronunciation with how you might pronounce the "o" in the word "show." Keep this distinction in mind as you work on your accent in Russian.http://masterrussian.com/aa032301a.shtml