is there an english grammer rule that tells us to use mom instead of my mom when talking to our sibling or oth

Answer 1

Think of it this way: "Mom," capitalized, is a proper noun, like your name or your siblings' names, so, when talking to family, "Mom" is more appropriate. "My mom" is fine with people who don't actually know your mother (or even if they do, but I think you get my meaning); it's more of a reference, like saying "my brother" instead of "Tom," or "my friend" instead of "Susie." With your siblings, saying "my mom" is a little possessive; it sort of implies that she's YOUR mother and not theirs too, so "our mom" would be better.

Although my brother and I sometimes refer to our mom as "your mother" ("Do you know what your mother said to me today?") if she did something to make us mad. ;-)

Answer 2

Yes, in fact, there is. When you refer to someone as my mom, it is an ordinary noun, and "my" is used to differentiate the person you are talking about from other moms. When you refer to someone as "Mom," you are talking about your mother, and you are using the word as a title, similar to a name. Thus, the capital M.

Answer 3

My siblings and I tease each other about that too. We have a habit of just saying "my mom" even when talking to our siblings, its because when we talk to others we say "my mom" does this or that. Saying "our mom" just isnt "programmed" into our vocab.

Answer 4

no.no specific rule. OTOH it is an instance where a common noun (mom) becomes a proper noun (Mom- referring to a specific person, rather than a generic term)

Answer 5

No, but I always considered it very bizarre when my brother would say "MY mother" when speaking to me about OUR mother. Like she was his alone or something.