kindly please correct my english grammar if it is correct or mistake.

how to use the word all.

1.all girls are beautiful.

2.all of them is really has a kind heart.

3.all peaple is good.

Your use of "all" are all correct.

Sentences begin with a capital letter -- so 1. should be "All girls are beautiful."

Other corrections:
2. All of them really have a kind heart.
3. All people are good.

Sure! I'd be happy to help correct your English grammar. Here are the corrected sentences:

1. All girls are beautiful. (This sentence is correct. "All" is used to refer to every girl, indicating that every girl is beautiful.)

2. All of them really have kind hearts. (The subject "them" is plural, so the verb "have" should also be plural. Additionally, "really has" should be changed to "really have" to match the correct subject-verb agreement.)

3. All people are good. (The word "people" is plural, so the verb should be "are" instead of "is." Additionally, "peaple" should be corrected to "people.")

Remember to use "all" when referring to the entirety or every member of a group, and make sure to match the verb form with the subject in terms of singular or plural.