Final answer:
The student needs to use the correct tenses in the given sentences.
Step-by-step explanation:
The first sentence should be: I think I do one unit every week.
The second sentence should be: My exam is on 15th May, so there is not any time to be lost.
The third sentence should be: If I pass my exam successfully, I will start an apprenticeship in September.
The fourth sentence should be: After my apprenticeship, maybe I will go back to London to work there for a while.
The fifth sentence should be: You can see I have become a real London fan already.
Learn more about Verb Tenses