We learn early in grammar school that in English, verbs have the handicap of not being able to inflect or morph by themselves into the future tense. To compensate for this, however, English came up with no less than six ways of evoking the future, as follows:
(1)
The simple future tense, which puts the auxiliary verb “will” ahead of the verb stem, as in “will take” in “The chairman
will take his retirement next month,” and
(2)
The future perfect tense, which uses the so-called temporal indicators to situate actions and events in various times in the future, as in the use of the future perfect “will have taken” in “
By this time next month, the chairman
will have taken his retirement.”
In both cases, instead of inflecting itself, the verb “take” took the expedient of harnessing one verb (“will”) or two auxiliary verbs (“will have”), respectively, to make its two visions of the future work.
Then English came up with four more grammatical stratagems to evoke the future tense, as follows:
(3)
The arranged future, also known as
the present continuous;
(4)
The predicted future;
(5)
The timetable future, also known as
the present simple; and
(6)
The described futures, also known as
the future continuous.
The future-tense type that you say confuses you—the one that uses the form “be going to + the verb’s base form”—is Form #4 above,
the predicted future. As in the first example you have given, “I am going to forget about you someday,” this form of the future tense uses the verb’s infinitive form preceded by the auxiliary phrase “going to.” It serves as a categorical forecast of what will happen based on what the speaker knows about the evolving present. (The alternative sentence you provided, “I am
gonna forget about you someday,” uses “gonna,” which, of course, is a colloquial contraction of “going to.”)
So how does the predicted future form differ from the simple future form below that uses “will forget”?
“I
will forget about you someday.”
The difference is that the simple-future form using “will” simply states that something will happen in the future, while the predicted-future form using “going to” categorically declares that the speaker will make a purposive effort to make the stated future outcome happen.
There are two other uses of the “going to” future-tense form:
(1) To express what people want to do, as in “
I’m going to think over your suggestion.” This form of the purposive future suggests that the speaker had thought about the action before speaking about it, as opposed to deciding on it spontaneously, in which case the simple future tense using “will” is more appropriate: “I
will think over your suggestion.”
(2) To express something that the speaker believes is impossible to avoid or prevent: “You know that the circus
is going to close this Friday.”
Statements in the predicted future form are shaped both by the information the speaker has about that future and how he or she wants that future to be. They can use a temporal indicator (as “someday” in your example) but don’t necessarily require it, as in “I
am going to forget about you.” When precise time frames are provided, the simple future tense is often preferable: “I
will forget about you someday.”
For a better understanding of the “be going to” form of the future tense, I am posting in this week’s edition of the Forum
“The Six Ways That English Reckons with the Future.” That essay introduces Section 7 – “Mastering the English Tenses” of my book
Give Your English the Winning Edge. The nine chapters in that section of the book provide an intensive discussion of the various future-tense forms in English and the usage of the adverbs of time.
