Vocabulary in Arabic is vast. No one knows for sure how many words there are in the language, as it is a living body of words and dialects that is constantly changing. The best estimates coming from Sakhr’s statistics is that Arabic has around 10,000 roots and 200,000 distinct words. Even if we could measure the number of words, it wouldn’t help you much day to day. For a solid foundation in the language, a smaller set of high-frequency words will do the trick. Here are high quality vocabulary lists grouped by category.
English Words with Arabic Origin