Is it grammatically acceptable to omit the term "house" in the following sentences:
"I had to go to my sister's to get my laptop because I had fogotten it there, that's why I took so long to come back home".
"I'm going to John's to visit him because he told me he was sick".
"Yesterday I went to Michael's, but he wasn't home".
It is indeed acceptable to omit "house," "home," "office" or "tipi" in the sentence
"I had to go to my sister's to get my laptop..."
Strictly speaking, such a construction is informal, since it requires that the reader assume the missing word.
In formal usage the omission would usually require that the absent word appear, as an antecedent, in a prior statement:
My house is a small cottage. My sister's is a sprawling ranch.
While omitting the antecedent word may run afoul of strict formal composition norms, it is perfectly clear in conversation or informal writing.
