Often syntax is poor when the subject is separated from the predicate by a long series of phrases or modifiers. Another problem of syntax is misplaced modifiers. The modifying phrases are so far away from the words they modify that the sentence sense becomes murky. When doing so, the antecedent is often unclear. This was a difficult project.
Historians often describe how events unfold or how one set of circumstances changes.
Use it sparingly. Substitute a different verb in most cases. Poor writers often use the same word or variations of it several times in succession. This organization proved to be the strongest in the region, and became a leader among organized laborers. Contractions are allowed in fiction, informal writing, or when quoting.