1. They were - was
happy last Sunday.
2. Sam were- was
upset because he failed his exam yesterday.
3. My friends were-was
so funny last time​

1. They were

happy last Sunday.

2. Sam was

upset because he failed his exam yesterday.

3. My friends were

so funny last time

Употребляя was/ were, помните, что was употребляется с местоимениями I, he, she, it, а were - с местоимениями we, you, they