@nielsinha488 my prep course provided us with a good dictionary that included all the common difficult words on the lsat. I found it helpful. PM me and I'll let you know more information.

English is my second language as well. Actually it's my fourth language lol I know french, Italian, Dutch, and English. I was in ESL class when I immigrated to united states.

I always look up the words I don't understand although I don't really recommend this because on the actual test day you won't have a dictionary to look at.

However, lsat doesn't test you on English. Luckily you can understand the core of the argument by reading the other sentences. I would recommend reading at night and talking more in English so that you can expand your English vocabulary. I would also recommend writing.