Future Perfect – Difference Between ‘I Will Write the Letter Tomorrow’ and ‘I Will Have Written the Letter Tomorrow’

future-perfect

What is the difference between "I will have written the letter tomorrow" and "I will write the letter tomorrow"?

Best Answer

To say I will write the letter tomorrow is a plain statement of intent in which you look forward at the present moment to an act you plan to carry out in the future.

To say I will have written the letter tomorrow is a way of looking back from a future point at an intended action that lies between the present and that future point.

We use this construction particularly for reassurance, whether to ourselves or a third party.

For example, a soldier might reflect: At this time tomorrow I will have completed my tour of duty.

And a builder might reassure an anxious householder: The house repairs will have been completed by tomorrow evening.

So the difference lies not in the future action itself but in the way that the speaker regards it - and the speaker's purpose.

Which construction you would prefer really depends on the context.