The Early Step of Grammar on Complexity

The circumstances exist along with the core. The expansion shows on the presence of markers (e.g in case, in the way that). The circumstances are realized by the placement of adverbial markers. That's why the following clause after (including the marker) is called adverbial clause (e.g in case it should be rain, in the way that I asked). There are adverbial clauses expressing reason, purpose, result, contrast, place, time, comparison, or manner.

"He is the technician whom I talked to"

Expanding idea is also realized on relative clause. It is started by relative pronoun (e.g whom). The clause following relative pronoun refers to relative clause (e.g whom I talked to).   This clause functions linking an entity to specific existence. This lesson should be taught as long as we teach complexity on sentence related to grammar.

This article is also dedicated for all my students, especially in complex English grammar who are learning the lesson in this semester. Be prepared for your exam. :D