Mom is what North Americans call their mother. The English use Mum or Mummy (Mummy more common for a younger child to use). The Irish use Mam or Mammy (Mammy also more common for a young child). I expect people from other English-speaking countries have other terms. Mom is not really used in Ireland or the UK, although everybody would understand the meaning of it.
First of all, Russian past tense is the only one where verbs change in the 3d person singular according to the gender of the subject.
So "Он продал" (He sold) and "Она продала" (She sold)
"Он продавал" (He was selling) and "Она продавала" (She was selling).
In present and future tenses verbs don't change this way.
"Он/она продаёт" (He/she sells)
"Он/она продаст" (He/she will sell), "Он/она будет продавать" (He/she will be selling)