From Teflpedia

Say (/seɪ/) is an English verb.[1] It is the most common lexical verb in English.

The meaning is different to speak, to talk or to tell and this may be difficult for students.

In the present tense it is regular, but we generally pronounce the present tense third person singular form, which takes a third person -s, "says" as /sez/ rather than /seɪz/. In the past tense it is an irregular lexical verb. "Said" (/sed/) is both the preterite and the past participle, the present participle is saying. It is a weak verb and follows a similar pattern to lay (lay-laid-laid) and pay (pay-paid-paid), but not bay, way or flay, slay, stay, etc, which are regular, or indeed may which is a full modal verb.

It is often used in reported speech for reporting speech.

It can be used as a noun, or adverb.

See also saying