sprechen

to speak with sb.

the person you speak with — who, not what about

Ich spreche mit dem Lehrer.

I am speaking with the teacher.

womit?damit

to talk about sth. — to discuss it properly

the topic of the conversation, at length and in substance

Wir sprechen über den Film.

We are discussing the film.

worüber?darüberdarüber, dass …

to mention sb. / sth. in passing

a passing mention, not a discussion — that is what separates it from über

Er sprach von seinem Bruder.

He mentioned his brother.

wovon?davon