<Your argument that it can't be the future tense because something else is the future tense denies that there can be two different future tenses.>
My argument was that if Uriel's statement "could ... is the future form of can" were true, we would not be able to say "You can call her tomorrow", because Uriel's statement excludes other future forms.
Thus Uriel's statement, not mine, "denies that there can be two different future [forms]". My comment points out this anomaly.
Uriel's response relates to non-exclusive forms, and therefore doesn't relate to my comment; although it might seem to support it.
The main problem with Uriel's earlier analysis is that it disregards backshift and the special character of modal verbs. But this statement that "could ... is the future form of can" would mislead any learners who took it literally:
A. I can do this today.
B. I could do this tomorrow. [The "future form" of A, for a learner misled by Uriel's comment.]
My argument was that if Uriel's statement "could ... is the future form of can" were true, we would not be able to say "You can call her tomorrow", because Uriel's statement excludes other future forms.
Thus Uriel's statement, not mine, "denies that there can be two different future [forms]". My comment points out this anomaly.
Uriel's response relates to non-exclusive forms, and therefore doesn't relate to my comment; although it might seem to support it.
The main problem with Uriel's earlier analysis is that it disregards backshift and the special character of modal verbs. But this statement that "could ... is the future form of can" would mislead any learners who took it literally:
A. I can do this today.
B. I could do this tomorrow. [The "future form" of A, for a learner misled by Uriel's comment.]