Final answer:
The sentence contains faulty parallelism because it combines a gerund phrase with a clause, which are not structurally parallel. It can be corrected by ensuring both parts of the sentence are similar in structure.
Step-by-step explanation:
The error in the sentence 'Knowing his tendency to oversleep and because he needed to be on time, Paul bought an alarm clock' is an instance of faulty parallelism (FP).
This is because the sentence begins with a gerund phrase 'Knowing his tendency to oversleep' and then switches to a clause 'because he needed to be on time'.
These two parts should be parallel in structure but are not, resulting in a mixed construction. It can be corrected by making both parts of the sentence similar in structure, such as 'Knowing his tendency to oversleep and needing to be on time, Paul bought an alarm clock.'