Today I have been organizing my English teaching materials and I came across (phrasal verb) some notes on say, tell, talk and speak.

Say- takes no object pronoun and we say things.

He said (that) he would go.
In this blog, I'm saying various things about these verbs.

Tell-takes an object pronoun and we tell people things.

He told me to shut the door.
I told him that I was hungry.

The difference between "talk" and "speak" is small, and gramatically there is NO difference. Basically, that means you cannot make a mistake (except with languages). Talking is usually informal. Speaking is more formal.

The president spoke to the people.
The employees were all talking before the boss began to speak.
Can I talk to you?     (This is an informal situation. We are friends).
Can I speak to you?  (It is likely that this is formal, or perhaps I am angry).
He speaks two languages NOT He talks two languages.