Originally Posted by PhillyChiefFan
What led you to believe that Sun doesn't speak English at all? I might have missed something
She never spoke English in front of Jin before until she was on the island, and the only scenes we have seen her in the sideways flashes, she is with Jin, so she may be able to speak it, she might just choose not to.
Or was there something that happened where we know she can't speak, that I missed??
Before the island, she learned English because she wanted to leave Jin, and never spoke it in front of him so that he wouldn't catch on.
In the Sideways, she's not married to Jin and seems to be in love with him. So there would be no reason for her to learn English. And if she did, there would be no reason to hide it from Jin.