'Whom' is simply a pronoun, the object case of WHO. Therefore it can be used with reference to the past, present or future, just as he/him, I/me, she/her, we/us, they/them are not time specific. It is the verb or the context which indicates the time of the event or situation, not the pronoun. 'Whom' is also formal, and most people now use WHO.
Some example sentences in various tenses, and showing formal and more usual usage:
PAST
Formal: Whom did you say you saw at the shops?
More usual: Who did you say you saw at the shops?PRESENT
Formal: This is John, the instructor with whom I am working today.
More usual: This is John, the instructor who is working with me today. FUTURE
Formal: Whom will you take to the concert on Saturday?
More usual: Who will you take to the concert on Saturday?Which is correct, Who or Whom?
'Who' is the subject case, 'whom' is the object case. However, in some sentence contructions it is not always easy to see which case to use. Also, even when the 'correct' case and form has been determined, it should be noted that the word 'whom' is not often used in informal English.
Present perfect, past perfect or future perfect.
The present perfect tense is used when there is a connection with the past and the present. It is used to depict change, experience and a continuing situation. The future perfect tense, however, is used to talk about the past in the future.
'Now' talks about the present so it can only be used in the present tense.
Past - was Present - is Future - will be
"Occupied" can be used in the past, present, or future tense. It is the past tense of "occupy", the present participle, and can also serve as an adjective to describe something that is currently being used or filled.
Present perfect, past perfect or future perfect.
The present perfect tense is used when there is a connection with the past and the present. It is used to depict change, experience and a continuing situation. The future perfect tense, however, is used to talk about the past in the future.
PV is used for present values and FV is used for future values.
The pronoun 'I' can never be used correctly with the verb 'is.'Correct ways of using 'is' in present, past, and future tense include:I am (PRESENT TENSE)I was (PAST TENSE)I will (FUTURE TENSE)She/he is (PRESENT TENSE)She/he was (PAST TENSE)She/he will (FUTURE TENSE)
'Now' talks about the present so it can only be used in the present tense.
There is a past, present, and future. There was a past; there is a present and there will be a future.
The past tense is used to refer to something that has already happened. The present tense is used to refer to something that is currently happening. The future tense is used to refer to things that have not yet happened but will happen in the future.
"Running" is the present participle of "run". Present participles are used to create the progressive tense. The future tense of "run" is "will run". The future progressive is "will be running".
Past - was Present - is Future - will be
"Occupied" can be used in the past, present, or future tense. It is the past tense of "occupy", the present participle, and can also serve as an adjective to describe something that is currently being used or filled.
He used to but he's past it by this present day
The word "harvest" can be used in present or future tense. Examples include "We are harvesting apples today" (present tense) and "We will harvest the crops next month" (future tense).