For all tenses, this is always the first element in the verb pattern to change with the time extent (PRESENT, PAST, or FUTURE). It changes the same in our Fields of Time. We can say that it is the form closest to our cognitive ground. It changes the same for our value ON.
The Simple and Progressive Aspects compared: "stative verb" use described with regard to human cognitive activity.
It is natural to wish someone good luck, with tests and exams. Grammar exercises can "buy" us some luck. The exercises do not have to be difficult, to work for our boutique d'bonheur.
When we read dictionaries, we remember that human brains do not have fixed connotations. A “squid” can be a marine animal. It may be a bird toy. “A bit of cosmos” may be a garden stretch grown with cosmos flowers to attract birds. Let us try our meticulous natures with real words and bigger dictionaries. We mind the time frame.
Written or spoken texts do not determine our inner language. We can learn to focus on the Aspect, gather our verb forms from elements, as well as take language tasks "at the drop of the hat", when our inner language integrates the essentials.
We exercise verb 1st and 2nd forms for the grammatical PRESENT, PAST, and FUTURE. In simple words, we learn to put verbs in Fields of Time.