To understand what an "auxiliary" verb is, it helps to first
make sure you understand the meaning of the word "auxiliary."
Auxiliary means: Providing supplementary or additional help and
Thus, an auxiliary verb is a verb used to help or support a main
There are different types of auxiliary verbs that are divided up
into the types of functions or grammatical meaning that they add
to clauses or sentences. For example:
Aspect: The way or manner in which the verb was done.
[How the action was done.]
Diathesis: Active voice or passive voice. [Is your
subject the doer or the receiver of the action? Example: "The ball hit the boy"
vs "The boy was hit by the ball."]
Emphasis: Is the verb being used to indicate special
importance, value, or prominence? [Example: WILL when used to emphasize that
someone will for sure do something.]
Modality: The degree to which something is likely, possible, or necessary.
[Example: CAN when used to indicate possibility, MUST which is used to indicate
necessity, and WILL when used to indicate that an action is a certainty.]
Tense: Indicating when the action or event happens.
[Example: The sign PAST when used to mean "was." For example: "PRO.1 PAST PLAN
GO BUT CHANGE MIND. = "I was going to go but I changed my mind."]
If you use the FUTURE sign with a double arc to mean "someday" as in "Someday
I'll go to go college" that is using the sign as an "auxiliary tense" verb.
If you use the sign FUTURE at the end of a sentence with a strong single
movement it is functioning as a modal auxiliary verb or emphasis auxiliary verb
expressing (and emphasizing) that it is a "very strong likelihood" that you will
be going to college. For example: "FUTURE-[someday] I GO COLLEGE, I WILL!"
Thus we see the sign FUTURE being used two different ways. At the beginning of
the sentence it is being used as a "tense" auxiliary verb. At the end of the
sentence it is being used as a modal or emphasis auxiliary verb.