I’m an EFL teacher and this is how well I think different death note characters can speak English:
L
No question here, he’s a native English speaker. Grew up in the UK and never spent time around anyone other than Watari. So, he has a neutral British accent. HE SHOULD’VE HAD ONE IN THE DUB!!!
Light
Near native speaker. He tries very hard to speak perfect English, but remnants of a Japanese accent will occasionally peak through. He mentally curses himself when this happens. He also speaks very formal English, because he probably learned it from an after school program or something.
Misa
Misa can’t speak or understand English. She is a big fan of Western culture though and can quote English pop culture references. When she does this, she has a very thick accent.
Mr. Yagami
Can speak English but not that well, he also has a very thick accent. He speaks very formally, because he learned from an adult English program, maybe through his job. He occasionally misunderstands slang or expressions.
Matsuda
Speaks English surprisingly well. This came as a shock to many of his co-workers. He learned in university and is a big fan of Western sitcoms. I can see him liking Seinfeld or something. When Light and Mr Yagami don’t know a word or an expression, he explains it to them and this infuriates Light XD
Aizawa
Aizawa gets very frustrated when talking to foreigners because he doesn’t speak English. He can say a few simple phrases in English, because of some mandatory courses he took in his police school days, but refuses to use any of them, because he’s insecure and is afraid it might make him look dumb.
