Question about tense

Re: Question about tense
In spoken English, the sentences mean basically the same thing and can be used more or less interchangeably. In written English, there are some subtle differences:




This is the simple future tense. By itself, the sentence does not tell us if the exact time that he will leave is known; it also doesn't tell us if the exact time that the leaving is completed is known. All it tells us is that the leaving will happpen.




This is the present progressive tense. By itself, the sentence suggests that his leaving the company has already begun but is not yet completed.




This is the future progressive tense. By itself, the sentence suggests that his leaving has not yet begun, that the exact time when it will begin is known, and that the exact time when it will end is not known.



In written English, any of these sentences could be used in place of each other. If you want to specify when the action will start and end, you don't necessarily have to rely on tense; you could supply that information with other sentences.