Question

when he arrives,i will let you know

explain why arrives came instead of will arrive??​

Answer 1

Answer:

The issue really has to do with your verb tenses: whether we should use the simple present or the present perfect, especially given that many people use them interchangeably. Here, I am weighing in on the use of the simple present as the more correct usage.

Generally, the present perfect tense is used when there are parallel time frames, one in the past that coincides with one in the present; “ I have studied the material since I was a teenager,” or “We have used that computer for many years now, and it still works.”

Using the present perfect with the future tense moves all the action into the future, so there is no present frame of reference. “When I have arrived” has not occurred yet. There is an underlying uncertainty as to whether the person will arrive at all. In other words, the meaning of the statement is “Should I ever arrive, I will let you know.” I believe, furthermore, that the construction is erroneous: we cannot use when and the present perfect tense together because the present perfect is not a future tense and does not denote futurity.

Rather, and preferably, we use the simple present to state that arrival is sure and imminent: “When I arrive, because I will, I will let you know.” The present tense denotes action that is happening now or is a habitual or regular occurrence. There is no doubt cast upon the state of arrival, as it is certain with the use of the present tense.

It also happens that the fewer words we use in English, the better it usually sounds. Just on the basis of economy of style, especially if we assume the meaning of the two sentences are equal, there is no reason to use more words. Again, the present tense wins out.