something about "say", "speak", "talk" and "tell"
These words of oral amd written English are all verbs; talk and say are also nouns. The verbs mainly differ in their grammar. Talk and speak are very similar; speak is more formal and less commonly used. I want to (talk)(speak) to/with you after work today. When my father was unhappy with me, he always (talked)(spoke) to me very formally.
What did the guests talk about? (here speak is too formal) How long did the president (talk)(speak)?
Don't (talk)(speak) for more than 20 minutes.
Talk and speak are often followed by words like to, with, about and for. We also say things like '(talk)( speak) slowly and clearly.'
You can say 'speak English'. We don't say 'talk English' unless one means talk about English.
You can not say '(Say)(Tell) English', but you can say 'Say (it)(something) in English.' and 'Tell me something in English.'
Say is very commonly used. What did he say? I didn't understand what he said. Say that again. Say it more slowly. I almost always agree with what he says. The weather man says it will be much colder tomorrow.
Say and tell are more commonly used for written things than talk and speak are. What did John say in his letter? The second chapter of the book will tell us about Napoleon's childhood.
Tell is almost aways immediately followed by a noun or pronoun that serves as a direct or indirect object.
Tell us more about yourself.
Tell (me)(Kate)(the class) what you did on Christmas Day.
I told the police what I saw.
I told my story to anyone who would listen.
When you (speak)(talk) to the students, what will you (say)(say to them)(tell them)?
I would agree that the verbs are similar and that 'speak' is less commonly used, but I think it is only a more formal word in certain cases.
With 'talk' there is more of a suggestion of an exchange (A↔B, where A = the subject and B = the one or more people the subject is talking to); with 'speak', more of an interest in what one person says (to another) (A→). I think that because most communication does involve an exchange (A↔B), 'talk' is much more common. However, there are cases where we might or must use 'speak'. Here are some examples:
'I'd better speak to him about his behaviour before he gets thrown out of school.' (A→ b) - 'talk' would also be fine here; with 'speak' the emphasis is on what one person has to say to another. (I've illustrated this with a lower-case 'b' - A dominates.) There is also a suggestion of the seriousness of the nature. As another example: 'I need to speak to you privately!' - here there is a suggestion of greater seriousness and possibly formality than 'talk'.
'After she had finished reading the letter, nobody spoke.' (A→(b)) - 'talk' is unlikely here because we are only interested in whether A ('nobody') had something to say and not who they had to say it to. (I've illustrated this with a bracketed '(b)' - B is hardly relevant).
In the following examples, we are only interested in the words that come out of one person's mouth (A→) - we have no interest in anybody else (B). In these cases we would use 'speak':
'She has lost the ability to speak.' 'She speaks French and German.'
Finally, in some cases we use 'speak' when one person (A) communicates to an audience (B) . Here, we often say 'give a speech' instead. Compare:
'I gave a speech to the audience.' - whilst you (B) listened in silence and clapped when I'd finished (A→) 'I gave a talk to the audience.' - whilst you (B) listened, maybe laughed, maybe interrrupted me with questions, etc (A→b)
From the above two examples, you'll see that 'speak'/'give a speech' is more common in formal situations when presenting before an audience.