all time

Both are correct.

she is from America. she is American.

Right

no, I am from Bangladesh.

are

you are american. are you american? both are correct because there a parson is a citizen of America. so we have to say/asked him/her are you American

false. correct are: you are not from America or you are not American

she is from England. she "is British " not England.

she is British. that is correct because England citizen are called british