Variations in English
The variations in the different forms of English can often be difficult to understand. For example, the difference between using formal and informal language or the differences between spoken and written language. This leads to students writing words phonetically, i.e. how they would say it rather than how its actually spelt, and using informal language, maybe even slang that they have picked up, in formal situations which may perhaps be viewed negatively.
Good luck in learning one of the most difficult languages in the world today…remember practice is the key.