Quote Originally Posted by Antonio1986 View Post
Привет.

What is the difference between "сказать" and "поговорить"? The only thing I understand is that they both indicate the future of "говорить".

спасибо!
1. Neither of them indicates future unless you put it into the future form.
The forms you have provided are the infinitive forms. The infinitive does not have any tense. But you can put it into the Past, the Future, or the Present. The Present is only available for the Imperfective verbs. The verbs you are asking about are Perfective, so they do not have Present, only Past and Future:

"Сказать"
Past:
Я сказал (I said, I told something).
Future:
Я скажу (I will say, I will tell something).

"Поговорить"
Past:
Я поговорил (I had a conversation with someone).
Future:
Я поговорю (I will have a converstation with someone).

2. What makes these verbs similar is that both of them are perfective (while "говорить" is imperfective).

If you are not familiar with the concept of the aspect (Perfective vs Imperfective), then you are going to listen to a long story about it, and there is a lot of things to understand (not possible to put it into a single post).

To make it simpler, first notice the fact the Imperfective verb can be used in any Tense:
Present: Я говорю. (I am speaking, or I speak).
Past: Я говорил. (I was speaking, or I used to speak).
Future: Я буду говорить. (I will be speaking).

The perfective verbs, as I wrote above, do not have Present, they can only be used in Past or in Future.

3. The difference between "сказать" and "поговорить" is in their meaning. "Cказать", as Wanja explained, indicates a one-time completed action:
Он сказал мне, что он не придёт. - He told me that he would not come.
"Поговорить" belongs to the class of verbs of the so-called "limited action" (which is indicated by the prefix "по-"). In fact, it means "to speak for some limited amount of time":
Я вчера поговорил с Петром. - Yesterday I talked to Peter (for a limited time duration, i.e. I had a conversation with him).