Hello Viognier

First of all, please understand I am not a linguistic expert. So I have no intention to contest with you about this kind of professional subject.

As you also know, there are many opinions about the concept of "tense" among experts. Some experts take the term "tenses" as grammatical categories expressed by verbal morphemes. But other experts think English tenses are partly made by verbal morphemes and partly by the use of auxiliary verbs.

To me, the two-tense concept is convenient to understand the historical development of the English language. The theory seems to be good to give reasons to the question why English has developed a variety of collocations to describe future events.

paco

Hello

Here is some information I got online

Future Tense in Old English

And now finally a few irregular verbs, which used several diffefrent stems for their tenses. These verbs are very important in Old English and are met very often in the texts: wesan (to be), béon (to be), gán (to go), dón (to do), willan (will). Mind that there was no future tense in the Old English language, and the future action was expressed by the Present forms, just sometimes using verbs of modality, willan (lit. "to wish to do") or sculan (lit. "to have to do").

English Tenses and Aspects

The English verbs are inflected for two tenses: present (walk(s)) and past (walked). In other words, tense is indicated by morphological marking: zero/-s for present tense and -ed for regular past tense. Tense is not necessarily straightforwardly related to what TIME the event represented by the verb takes place. For instance, the simple present tense can be used to refer to various times, as it is used for (1) events which happen regularly or habitually: He smokes, drinks, betrays people and has no guilt whatsoever. (2) timeless truths: The sun rises in the east.  (3) present events: I declare the meeting open. Bremner passes the ball to Lorimer.  (4) historic present, especially in literary English but also in oral narrative. It recalls or recounts the past as vivivdly as if it were present: He just walks into the room and sits down in front of the fire without saying a word to anyone.  (5) events that are expected to happen in the future: When he returns to Manhattan 1000 years later, it has been destroyed and rebuilt three times.

2. What about time then?

We can, of course, situate events in time, but this is not only done by means of grammatical tense. The two tenses, past and present, combine with the aspects discussed below to indicate how the event is viewed in relation to time. In the time-line perspective, we can talk about the past, present and future time. To take an example, English, unlike many other languages, does not have a separate verb form for the future. Consequently, there is no future tense in English, even though there are, of course, many different ways in which we can talk about the future time: (1) The parcel will arrive tomorrow. (modal auxiliary will) (2) The parcel is going to arrive tomorrow. (be going to) (3) The parcel is arriving tomorrow. (present progressive) (4) The parcel arrives tomorrow.  (simple present) (5) The parcel will be arriving tomorrow.  (modal auxiliary will + progressive aspect)

paco