I guess it depends a bit on your friend's current level of English.
When I started the game, my English was honestly terrible; I was really slow at reading and kept a translator at hand for the most complex sentences.
Some NPC dialogues (like with Baderon) left me scratching my head trying to figure out what they were saying, luckily when I leveled an alt my bf would translate for me in normal English.
It may sound silly but the thing that really helped me was reading FC chat with people bantering and listening (albeit with some difficulties because accents) to them talk on voice chat.
Not to mention, I asked to be corrected in case I wrote/said something weird haha.
And when I got enough courage I attempted to speak, I think that was the hardest part for me and sometimes I still struggle with some words.