Say vs. Speak

[Jupiter]

Hi teachers,

Please look at the following:

I spoke to John yesterday.
I talked to John yesterday.

What is the difference?
Could you shed some light on how to use say and speak?

Thanls in advance

Jupiter

[Conchita]

Here are two threads that will be of help:

Speak vs say
http://www.english-test.net/forum/ftopic831.html

May I talk with Alan?
http://www.english-test.net/forum/ftopic5827.html