I Should Never Stop Learning English. Absolutely Not!

Indonesian is the colloquial language used at my office. (2) This helps me to work faster, because I don't need to translate Indonesian to English or vice versa. But I sometimes find it difficult when looking for literature(3). There's a lot of literature written in English. In fact, sometimes you can only find what you are looking for in English. When that happens, inevitably I have to translate the literature. 

Another case I found is when I must assisting customers in audit activities, especially from foreign auditors. Of course the language used is English. In this case, I had help from a translator. (4)

I should never stop learning English. Absolutely not! English is the lingua franca (5) used throughout the world, so I'll find it everywhere and all the time.

(1) "studied" would be a better word here.

(2) I took the last sentence of the previous paragraph and moved it to this paragraph because it establishes the theme, and makes the next sentence clearer.

(3) "Literature"? Are you looking for literature at work? This is confusing. Usually, "literature" is used to talk about novels. I suspect you mean a different noun, but I am not sure what word it would be. There are a few possibilities. If I knew what you did for work, I might be able to guess.

(4) It is hard to tell whether this happened once, or is something that happens regularly. It's difficult for me to correct it without knowing which is the case.

(5) I know what you meant by "official language", but English isn't the official language of almost anything. It is, however, the "lingua franca" of international business.

You did a very good job, especially for not having studied English in over two years.