"The verb forms of be, do, and have can be used either as a main (full) verb or an auxiliary verb,"  we can learn online, as from TALK ENGLISH. We can read about auxiliaries and main verbs many places. The good trick you can get only here is: verbs can help tell "where" we are in our thoughts about time.


Real-life and real-time, thinking when a verb is auxiliary, and when it is the main verb might slow us down very much. Besides, verbs are often head verbs. They are not always strictly the main verbs in what we say.

The simplest resolve is to think where we are in our thought, and what we are talking about.

Our mind trick is to think about time as about a place. Grammatical time is not literally the time by the hour, anyway. It is psychological more. On a day, we might say it has been beautiful, in the evening. If we hate grammar tests, we might say the day was a nightmare, just getting back from school.

To learn this psychological time, we can exercise as about places, at first. Could there be a town named Tomorrow? There might be not many place names that derive from time, but they are not impossible.

We can envision our grammatical time in three fields, for the PRESENT, PAST, and FUTURE. These are the Fields to tell where we are in our thoughts about time.

Not only with grammar, our perspectives depend on our knowledge. We could say that our knowledge is the light we have. Knowledge needs memory. PAST things happen to go into oblivion, as the learning matter we do not review or work with. We can envision the light as with a setting sun: there is shine enough, if we want to return to the matter.

We do not have memories of the FUTURE, but we can plan our learning. Our shine can be as with sunrise.

It is our PRESENT we have the most potential to shape. The sun is high, and daylight broad.

We can picture the verbs BE, HAVE, and DO in our Fields of Time. Here is the verb TO BE in the field for the PRESENT.

It is not difficult to picture the verb TO BE in the other fields.

TRAVEL IN GRAMMAR has all the verbs pictured, in CHAPTER 1. On their own in the Fields, BE, HAVE and DO are going to be head verbs.

When we get to the River of Time, we will see BE, HAVE, and DO in patterns. In those patterns, BE, HAVE, and DO can be auxiliaries. Important: as auxiliaries, the BE, HAVE, and DO are still going to be the words to tell where we are in our thoughts about time. We can mark them in green, as auxiliaries. As head verbs, they can be color mauve. See also how COLORS CAN HELP READ AND LEARN.