1. I have a mother, father and brother.
2. I have Mother, Father, and a brother.
3. I have mother, father, and a brother.
4. I have Mother, Father, and Brother.
5. I have my mother, my father, and my brother.
6. I have my mother, father, and brother.
7. There are four in my family:my father, my mother, my brother, and me.
8. There are four in my family:my father, my mother, my brother, and I.
9. There are four in my family:my father, mother, brother, and I.
(Would you check the sentences? Which ones are grammatical and commonly used?)
1 needs a comma after "father"
2 and 4 need no capital letters except at the beginning.
3, 5, and 6 are OK.
7 is incorrect; 8 is correct; both need to have a space after the colon.
9 is fine if you put a space after the colon.
All of the sentences you provided are grammatically correct and can be commonly used. However, the preferred style might vary depending on the context or personal preference. Here is a breakdown:
1. I have a mother, father, and brother. ✓
2. I have Mother, Father, and a brother. ✓
3. I have mother, father, and a brother. ✓
4. I have Mother, Father, and Brother. ✓
5. I have my mother, my father, and my brother. ✓
6. I have my mother, father, and brother. ✓
7. There are four in my family: my father, my mother, my brother, and me. ✓
8. There are four in my family: my father, my mother, my brother, and I. ✓
9. There are four in my family: my father, mother, brother, and I. ✓
All of the sentences express the same idea, which is that the person has a mother, father, and brother as part of their family. The variations occur in the use of capitalization, the inclusion of possessive pronouns ("my") or definite articles ("the"), and the use of "me" or "I" at the end.
In everyday use, it is common to use a mix of these styles. However, it is generally recommended to use consistent capitalization and either all possessive pronouns ("my") or definite articles ("the") throughout the sentence for clarity and consistency.