Learn Italian: Conosco bene questo settore perché ci lavoro da anni. - I know this sector well because I have been working in it for years.

We use conoscere (here conjugated as conosco) because it means to be familiar with a person, place, or thing. Since "this sector" (questo settore) is a thing you are familiar with, conoscere is the right choice. Sapere is for knowing facts or knowing how to do a skill.

What does the little word ci do in ci lavoro?

In this sentence, ci acts as a location pronoun meaning "in it" or "there". It replaces the location so you do not have to repeat "in this sector". Instead of saying lavoro in questo settore da anni, you can just say ci lavoro da anni.

Why is lavoro in the present tense when the English translation says "I have been working"?

When an action started in the past and is still happening right now, Italian uses the present tense combined with da (for/since). English uses the present perfect continuous for this, but Italian simply expresses it as "I work in it for years".

Why does bene come right after the verb instead of at the end of the sentence?