Learn Russian: Я тебя очень люблю.

In this sentence, "you" is the direct object, meaning it is the person receiving the action of being loved. Direct objects in Russian are put into the Accusative case. The basic word ты (you) changes to its Accusative form, тебя.

Why is тебя placed before the verb instead of after it?

Russian word order is very flexible. Putting the object pronoun (тебя) before the verb is the most natural and common way to say this phrase. Saying Я очень люблю тебя is also correct, but Я тебя очень люблю sounds more native and flows better.

The English translation says "very much", but the Russian sentence only uses очень. Is there a missing word?

No, очень handles both "very" and "very much" when it describes an action. You simply say очень люблю (literally "very I-love") to express that you love someone or something a lot.

Why does the verb люблю end in -ю?

The dictionary form of the verb is любить (to love). Whenever the subject doing the action is Я (I), the verb must change its ending to match. For this verb, the "I" form becomes люблю.