Business English: A Practice Book by Rose Buhlig

14. Let me know if you ---- not be able to come.

=Exercise 106= Change the italicized verbs to past tense, future, present perfect, past perfect, future perfect. Wherever necessary, add sufficient to make the meaning of the tense clear; as, _Present_: The manager _is now_ in his office. _Past_: The manager _was_ in his office _a few minutes ago_. _Future_: The manager _will be_ in his office _to-morrow at ten o'clock_. _Present Perfect_: The manager _has been_ in his office _all the morning_. (It is still morning.) _Past Perfect_: The manager _had been_ in his office _only a few moments when the president arrived_. _Future Perfect_: _In about five minutes_ the manager _will have been_ in the president's office _exactly three hours_.