The structural parts of speech

(1) the preposition (in, on, below, under, between ~ place and direction; time~ after, before, till, until, at; abstract relations ~ by, with, because of, with a view)

The preposition is a structural part of speech which denotes the relations between objects and phenomena. It shows the relations between a noun or a pronoun and other words.

(2) the conjunction

The conjunction is a structural part of speech which denotes connections between objects and phenomena. It connects parts of the sentence, clauses, and sentences.

As to their function conjunctions fall under two classes:

coordinating (coordinating conjunctions join coordinate clauses in a compound sentence or homogenous parts in a simple sentence, or homogeneous subordinate clauses in a complex sentence, or independent sentences) ~ and, as well as, neither…nor, not only…but also, or, either…or, but, while, whereas, so, for;

subordinating (subordinating conjunctions join a subordinate (dependent) clause) to a principal clause) ~ that, if, while, though, as if.

(3) the particle (only, just, but, barely, merely, solely, simply, still, just, yet, quite, even, too, also, not (negative particle), never)