This sentence has the better parallel structure: If you write well, speak well, and are using good interpersonal skills, you will do well in this corporation.
Explanation:
Parallel structure is the repeat of a grammar form selected in a single sentence (also referred to as parallelization). By using the same grammatical template for each object or concept linked in your sentence, you develop a parallel structure.
While linking clauses to a coordinating conjunction including for, versus or but, so, or yet, a parallel organized form should be used.
Several examples have included the following:
correct: we prepare our bed in the morning, eat breakfast and feed the dog. Incorrect: We render our bed in the morning, finish breakfast and nourish our dog.
