Many international students who arrive at a college to study in English can speak the language well enough for normal life: shopping, travelling and meeting people. But the same students are often surprised to find that writing essays and reports in English is much more difficult. It can be helpful to think about the reasons for this situation.
Firstly, speaking is usually done face to face. If your listener can't understand you, then they can look puzzled and ask you to repeat. But this doesn't work with a reader! When we write, we usually have little idea who may read our work, so we have to write as clearly as possible so that it is easy to understand.
With academic writing, writers and readers have to learn special conventions: such as using capital letters in certain places. If you do not follow these conventions your meaning may be unclear and your teacher may have difficulty assessing your work.
Another issue is vocabulary. Most academic subjects require writers to use semi-formal language which is different from the idiomatic language used in speech. One example is using verbs like 'continue' instead of phrasal verbs such as 'go on'. In addition, all subjects use words in special ways which have to be learnt: for example in Political Science 'actor' has a particular meaning which is unconnected to the theatre.
