The first one is correct. The second one is also correct, apart from the fact that it's "mother" instead of grandmother. Grandmother would be 할머니. Also, which is less important, the food "is tasty", not "was tasty" (which would be 맛있었어요) The third is also correct apart from that it's "is teacher Lee Min Soo" (which implies that the teacher is still working at the same university, but doesn't teach that subject anymore). Your translation would result in "선생님이었어요" Fourth one is nearly right: "This is the picture that Steven took in Seoul" (implying a situation in which one person shows pictures to another person) "키가 크고 안경을 낀 남자는 누구예요?" This sentences translates to "Who is the tall man who wears glasses?" (키가 크다 means tall and 안경을 끼다 means to wear glasses)