So, what would you call "I will walk?"
I would call it a modal verb. That is not a TENSE. you have not modified the verb in any way. eg. "I walk" present and "I walked" past, no modification of the verb "walk" in the sentence "I will walk"
I said english has no future TENSE. English does have a variety of ways of expressing the future. We just use other means (modal verbs, "going to", present continuous for future, etc.
I didnt say english has no future, it has no future TENSE.
heres the academic reply:In Germanic languages, including English, the usual expression of the future is using the present tense, with the futurity expressed using words that imply future action ("'I go' or 'I am going' to Berlin tomorrow."). There is no simple future tense as such.
English has two true tenses, past and present (sometimes analysed as non-past). These are distinguished by the inflection of the verb, either ablaut or a suffix -ed (walks ~ walked, sings ~ sang). What is commonly called the future tense in English is not a true tense, but a modal construction that does not always appear (it is optional in subordinate constructions such as I hope you (will) go tomorrow, and is prohibited with other modals as in I can go tomorrow, but past tense cannot be similarly omitted: *I hope you go yesterday, *I can go yesterday).
This reality, that expression of futurity in English is a function of the present tense, is born out by the ability to negate the implication of futurity without making any change to the auxiliary construction. When a verbal construction that suggests futurity (such as "I shall go") is subsequently followed by information that establishes a condition or presupposition, or the active verb stem itself contradicts a future indicative application of the construction, then any sense of future tense is negated - especially when the auxiliary will is used within its literal meaning, which is to voluntarily 'will' an action.