Learn Russian: Если бы ты был готов, мы бы начали перерабатывать мусор сегодня. - If you were ready, we would start recycling trash today.

This sentence uses an unreal conditional (talking about something that isn't actually happening). In Russian, you always form these by using the particle бы along with the past tense of the verb, regardless of whether you are talking about the past, present, or future!

Why use the short form готов instead of the regular adjective готовый?

The short-form adjective готов is used because being ready is a temporary state for this specific moment. If you used готовый, it would sound strange, almost like you are describing a person who is permanently ready by nature.

Why is перерабатывать imperfective, while начали is perfective?

In Russian, verbs that express the start, continuation, or end of an action (like начали) must always be followed by an imperfective infinitive. This is because the second verb describes the actual ongoing process you are starting to do.

Does the word бы always have to go exactly where it is in this sentence?

In the first clause, бы almost always attaches directly to Если. In the main clause, бы is quite flexible, but it naturally prefers to stick to the pronoun or the first stressed word. Saying мы начали бы is also grammatically correct, but мы бы начали flows much better.