Speak较为端庄，表明别人(即讲者)在一段会话中常说得话较其他人比较多。
举例说明：
The Principal speaks to us every morning at the assembly.
Tom, your boss wants to speak to you.
Talk不如speak端庄，并且多用以讲话，少用以撰写。 Talk表明2个或大量的人到会话。
举例说明：
The students were talking loudly in the classroom, in the very presence of the teacher.
当宾语是一种語言时，要用 speak 无需 talk 或 say：
恰当： Victor speaks fluent Putonghua.
不正确： Victor talks fluent Putonghua.
不正确： Victor says fluent Putonghua.
在书面形式英文， talk 非常少作为及物动词，除非是在 talk 后接用下列的宾语：
Stop talking nonsense.
They are talking business again.
要不是接用上列的宾语，talk 后必不可少接用前置词 about。
举例说明：
恰当： Betty and Susan are talking about the trip to London.
不正确： Betty and Susan are talking their trip to London.
Say一般 跟讲者常说得话一起应用，无论是直述句或陈述句：
Please say hello / thank you to your mum.
What did your father say when you told him about your plan to get married? 'I cant believe it,' he said.
He said that he could not believe it.
但是， say 有时候也可用以一些非直述句或陈述句中。
看一下下列的事例：
I want you to say something about how we met at our wedding party.
留意 something about how we met并并不是用以转述他人常说的真正句子。
另一方面， tell 并并不是用以转述他人常说的语句，只是表述他人的讲话中上述的客观事实或材料：
He told me about the accident.
He told his parents the truth.
He told us a funny story.
在阐述命令句中，运用 tell 而无需 say：
'Keep quiet,' the teacher said to the students.
The teacher told the students to keep quiet.
'Dont stay up late,' my mother said to me.
My mother told me not to stay up late.
