Here's my analysis of the essay in last week's lesson:
If you look at the 'skeleton' of my essay (introduction, first sentence of each body paragraph, conclusion), you can see that I answer the question very clearly. Then, within the body paragraphs there are well-developed ideas to support my answer.
Coherence and cohesion (i.e. organisation)
I used my normal method: 4 paragraphs containing 13 sentences in total. The essay is easy to read because it is well organised and the ideas are developed in a very clear, logical way. Linking words (e.g. and, similarly, this, for example, mentioned above, firstly, secondly, finally, while, which) are used to connect ideas, but the linking doesn't distract the reader from the content.
I reviewed the good vocabulary in this lesson. Remember that your vocabulary score comes from your use of 'topic vocabulary', not linking words or phrases.
The essay contains a mix of long and short sentences, and there are no mistakes. Remember: as soon as you use connecting words like and, while or which, you will automatically create compound or complex sentences, so there's no need to worry about "complex grammatical structures".