(+) I was a stamp collector.
(-) I was not a stamp collector.
(?) Was I a stamp collector?
(+) He was busy yesterday.
(-) He was not busy yesterday.
(?) Was he busy yesterday?
(+) He was happy because of me.
(-) He was not happy because of me.
(?) Was he happy because of me?
(+) Rina was the smartest student in the class.
(-) Rina was not the smartest student in the class.
(?) Was Rina the smartest student in the class?
(+) They were home last night.
(-) They were not home last night.
(?) Were they home last night?