Was Cleopatra egyptian?
No, she wasn't. She was Greek. She belonged to the Ptolemaic dynasty who ruled after Alexander The Great. She was the first in her family to learn Egyptian.
Did viking warriors wear horned-helmets in war?
No, they didn't wear horned-helmets. They wore leather headgear or they didn't wear anything.
Did you study English yesterday morning?
Yes, I studied English / No, I didn't study English (yesterday morning)