Choose the correct answer1 they taught (themselves/themself) to play the guitar2

Choose the correct answer
1 they taught (themselves/themself) to play the guitar
2 my little brother is old enough to dress (him/himself)
3 my friend and i help (each others/ourselves) to do our homework
4 has (anyone/someone) seen my glasses? I cant find them
5 (neither/none) of my parents can play the piano
6 I have two apples. I'll eat one and give (other/the other) to my sister