NOT A TEACHER
Every / everybody / everyone / everything are singular words, so we use a singular verb.
But we use they/them/their after everybody/everyone:
- Everybody said they enjoyed themselves (=everybody enjoyed himself or herself)
(English Grammar in Use - Raymond Murphy)
- I don't understand nothing. Double negation. Many people object to this construction.
- I don't understand anything. OK.
- Me and my friends went to see a movie last night. Possible, but it's rather informal.
- My friends and I went to see a movie last night. OK.