Questions 2-10 choose the correct form of either SER or ESTAR. These Spanish verbs both mean "to be" in English. There are only 3 forms of the verb "to be" in English: am/is/are. In Spanish, SER has its own 5 forms and ESTAR has its own 5 forms. So, you have to know the 5 forms for SER and the 5 forms of ESTAR. Then, you have to know the rules for when to use SER and the rules for when to use ESTAR.