An excellent skill for an ESL learner to have is the ability to distinguish objective and subjective language, and then to be able to write objectively when the situation requires it.
In business, it is important to state issues objectively when writing reports. In the academic world, it is important when writing a paper.
Here are notes on this topic for general learners:
http://www.roadtogrammar.com/notes/objective.html
Here is the accompanying activity:
http://roadtogrammar.com/?objective
Here are notes on this topic for learners of business English:
http://roadtogrammar.com/businessenglish/notes/?ref=objective
Here is the accompanying activity:
http://roadtogrammar.com/businessenglish/quiz.html?objective