ansprechen and besprechen!
is there a difference between ansprechen and besprechen?
besprechen= discuss; ansprechen= speak to, Er spricht mich an (He's speaking/talking to me.), to ask, Ich werde Herrn Sewald ansprechen (I'll ask Mr. Sewald.) and several other meanings, i.e. Diese Art von Malerei spricht mich nicht an (This style of painting doesn't appeal to me);
Ansprechen: To talk to a person. For example, you go out to a street and begin to speak with a total stranger. However "Ansprechen" is the act of doing 'it'.
Besprechen: The definition of it is, that you 'discuss something'. It literally means discuss something, if I am not wrong as a native speaker. So usually, if someone comes to you and say "we have to talk" (Wir müssen etwas besprechen), then most likely it will be something serious or semi-serious when you do a meeting. I hope I could explained it to you properly.
There is also a grammatical difference:
besprechen - besprach - besprochen (Infinitiv - Präteritum - Patizip II)
The verb "besprechen" has a prefix, that can't be separated. So the Partizip II does not need the prefix "ge-"
ansprechen - sprach an - angesprochen
This verb is constructed with the Prefix "an-" which is separated while conjugating. So you need for the Partizip II the prefix "ge-"
In addition to what especially Janfox5 and FrankEdger said:
"Wir müssen dieses Thema besprechen" = "We need to discuss this topic"
"Wir müssen dieses Thema ansprechen" = "We need to address this topic" (cf. what Janfox5 said about addressing / beginning a conversation with a stranger on the street)