Breakdown of Я не знаю, что он делает.
не
not
он
he / it (for a masculine noun) / it (for a neuter noun)
я
I
что
what
Questions & Answers about Я не знаю, что он делает.
Why do the verbs знаю and делает end differently if they are both in the present tense?
In Russian, verb endings change depending on who is doing the action. Both of these are first conjugation verbs (their dictionary forms end in -ать: знать and делать). For the "I" (я) form, you drop the -ть and add -ю, giving us знаю (I know). For the "he" (он) form, you add -ет, giving us делает (he does).
The English translation says "he is doing," but where is the word for "is" in the Russian sentence?
Is the word что pronounced with a "ch" sound?
No, it is an important exception! Even though the letter ч normally makes a "ch" sound, the word что is pronounced "shto" (starting with a "sh" sound). It is one of the most common words in Russian, so it is a great pronunciation exception to memorize early.
Why is there a comma right before что?
In Russian, you must always put a comma before question words like что (what/that), кто (who), or где (where) when they connect two halves of a sentence. English often skips this comma, but Russian grammar is very strict about including it.