Which of the following two sentences is correct?

He must decide who to be.

He must decide whom to be.

I can think of arguments for both sides, but I'm not sure.

To elaborate, is who(m) the object of decide, the subject of be, or the object of be? Does the infinitive form of be have any bearing on the answer? And is there anything else to consider about the position or role of who(m) in this particular sentence that would inform the answer?

The answers to the linked question What’s the rule for using “who” and “whom” correctly? say to "substitute he and him for who and whom." However, that doesn't give a clear answer in this context, because neither of those pronouns sounds right: "He must decide to be he"? "He must decide to be him"? Normally we'd use a reflexive pronoun here ("He must decide to be himself") and it's not clear what case that corresponds to.

  • Being the object of decide, it's whom. A construction using who would be He must decide who he is, where the whole clause is taken to be the object.
    – Anonym
    Dec 16, 2015 at 3:44
  • 4
    It's actually "who" in this case. The important verb is "to be", which doesn't take an object.
    – ralph.m
    Dec 16, 2015 at 4:22
  • 3
    @Anonym It's not that simple question.
    – user140086
    Dec 16, 2015 at 4:22
  • 5
    Since whom is often misused as an overcorrection, the current recommendation is, When in doubt, use who. That way, if you make a mistake (either way), it will seem less pretentious. Dec 16, 2015 at 5:43
  • 2
    @RegDwigнt: "Be" takes a complement, not an object. I think it should be "be whoever you want".
    – herisson
    Dec 20, 2016 at 7:22

6 Answers 6


The Wikipedia link about the accusative case explains that

Modern English, which almost entirely lacks declension in its nouns, does not have an explicitly marked accusative case even in the pronouns. Such forms as whom, them, and her derive rather from the old Germanic dative forms, of which the -m and -r endings are characteristic.

Now, whether to use who or whom in your sentence entirely depends on which case should be used, accusative (whom) or nominative (who).

In English, it is grammatically correct to use nominative after the verb to be as in

It's he who stole my car. It's they who told me the truth. It's she who lied to me.

However, we know that "It's me" (using the accusative case after to be) is broadly used in English. But it is just a few exceptions.

In your sentence, it is appropriate to use the nominative case as it is the complement of to be. If you divide the sentence into two parts:

He must decide / He should be who => He must ask who he should be => He must decide who to be.

in the same way as:

He must decide / He should meet whom => He must decide whom he should meet => He must decide whom to meet.

He must ask / She is who => He must ask who she is. (This question cannot be shortened with wh-word + to-infinitive as the subjects are not same.)

We don't ask,

*Whom is he? or *Who is him?

*Whom am I? or *Who am me?

because whom and him/me are the accusative case and can't be a complement of the verb be in this case.

Note: "He must decide who he wants to be" is more idiomatic than "he must decide who to be".

  • If this is the case, then why do we say I want him to be here instead of *I want he to be here? Why do we say I consider them to be useless instead of *I consider they to be useless?
    – Anonym
    Dec 16, 2015 at 6:00
  • @Anonym Because want and consider are transitive verbs. To be is not a transitive verb.
    – user140086
    Dec 16, 2015 at 6:54
  • 1
    @RJH The verb decide takes who to be as an object, not who itself. That is well explained above.
    – user140086
    Dec 16, 2015 at 7:00
  • 1
    @Rathony: That's not a useful argument, and anyway you completely missed the point. The article claims that Beethoven, whom you believe [or whom you believe to be] a great composer, wrote only one opera is correct. Why is it whom here instead of who when we have the verb to be? Why can the pronoun be the object of believe but not decide? Feel free to convince me with a better argument than "Shakespeare". I'm not arguing for the sake of argument. I'm genuinely questioning. Certainly no one has explained it here yet.
    – RJH
    Dec 16, 2015 at 7:21
  • 1
    @RJH Contrast "I believe him to be a great composer" with "I believe he to be a great composer". Which case is it? It should be the accusative case. Contrast "Beethoven, who I believe is a great composer" with "Beethoven, whom I believe is a great composer". Which case is it? It should be the nominative case.
    – user140086
    Dec 16, 2015 at 7:23

It would be

He must decide who to be.



is a subjective pronoun and

to be

is a verb, and subjective pronouns have to be the subject of a verb. Whom is an objective pronoun, so it would have to be the object of decide, which it isn't. If it were to be the object of decide, the sentence would have to be written thus:

He must decide whom he will be.

This is an example, and

will be

could be exchanged for

is to be,
should be,

etc. as the writer desires.

  • 1
    Not that I disagree with your conclusion, but the way you started your argument sounds like circular reasoning: (1) who is a subject, (2) subjects are subjects of verbs, (3) to be is a verb, thus (4) who has to be correct.
    – Michael
    Dec 16, 2015 at 5:22
  • If this is the case, then why do we say I want him to be here instead of *I want he to be here? Why do we say I consider them to be useless instead of *I consider they to be useless?
    – Anonym
    Dec 16, 2015 at 5:49
  • The verb tense of to be doesn't necessarily change the pronoun case, given that to be is a copula – even with the additional instance of the pronoun he. In the end, the sense is arguably still to be who(m). Whether to use the subjective or objective case in this sense is much disputed. There are arguments for both, which are further complicated by the fact that whom itself is falling out of favor. I think that traditional grammars would prescribe who he will be, not whom he will be.
    – RJH
    Dec 16, 2015 at 6:11
  • @Michael It was past midnight for me when I wrote that, and though it made perfect sense then, I can see problems with it now. If you saw the links I made, you will see what I was basing my point off of. The problem is that I said that "whom" would have to be the object of decide. This is not true; it should then be the object of the subject, He. You could also write the sentence so: He should decide to be who/whom? where who/whom is the object of the subject He, being the person he is deciding about becoming. And we would put "him" there instead: He should decide to be him.
    – wariya
    Dec 16, 2015 at 12:53
  • @wariya -- I agree that this is a tricky case. I also did not intend harm with my comment. I actually find circular reasoning funny since it reminds me of the film Idiocracy. Sometimes we understand a point better than we can express quickly and accurately in words. This happens to me too.
    – Michael
    Dec 16, 2015 at 17:27

When fronted "who" is a predicative complement, as it is in your example, it is always nominative.

  • I don't know who downvoted here. I was about to upvote, after checking your claim, but the lack of attribution (and this one seems not to be from CGEL) of this near-enough quote held me back. Aug 20, 2016 at 16:40

He must decide who to be.

This is correct grammatically (but as noted elsewhere, it is not a sentence that you would see in general use, if ever).

He must decide who to appoint. // He must decide whom to appoint.

The latter is grammatically correct, however "whom" can run the risk of sounding archaic and/or pretentious, even when used in the proper way, so it is often reserved for really obvious instances where "who" looks or sounds distinctly incorrect.


He must decide who(m) to be.

We can tell that “who(m)” in this sentence isn't the subject of "to be" because the meaning of the sentence requires the subject to be "he" (or an empty element with "he" as the antecedent). It means the same thing as "He must decide who he will be" and not the same thing as "He must decide who will be."

I think this sentence has the same structure as a sentence like

He must decide [to be an adult].

In other words, the pronoun “who(m)” is the complement of the verb "to be". This corresponds perfectly with the meaning of the sentence. The position of the pronoun “who(m)” in front of “to be” is regular due to the process of fronting. If we mark the original position of the pronoun with a “trace” t1, we get the following representation of the structure:

He must decide [who(m)1 to be t1].

Now, as mentioned in the question, both nominative and accusative pronouns sound odd after “decide to be” for semantic reasons.

However, if we compare this to other sentences containing "to be" with similar structure but different semantics, we find that the nominative seems to have been historically prescribed in this grammatical context. Correct English, Volumes 20-21, edited by Josephine Turck Baker, from 1919, says that the following sentences are "correct":

  • It was supposed to be I who made the error.
  • It was thought to be he to whom the speaker referred.
  • I should like to be he/she.

I think this addresses Anonym’s point about “I want him to be here”: quite simply, Baker treats “to be” differently depending on whether it’s explicitly preceded by an accusative pronoun. And in a sentence like "He must decide to be an adult", there is no accusative pronoun, so Baker (and presumably other prescriptivists like her) would consider it incorrect to make the complement of "to be" accusative in this context.

As Rathony said in a comment, “The verb decide takes who to be as an object, not who itself.”

The fact that “decide” works this way is simply a fact about this particular verb in modern English.

Now, all of this rests on my original analysis of the structure of the sentence, which might be wrong (I'm not a syntax expert), although BillJ's answer seems to assume more or less the same structure I've presented here.

"Who" certainly sounds OK here, so even if I'm not 100% certain "whom" would be wrong, I'm confident enough to recommend "who" over "whom" here. As medica said in a comment,

Since whom is often misused as an overcorrection, the current recommendation is, When in doubt, use who. That way, if you make a mistake (either way), it will seem less pretentious.


In this context, "who he is" and "who to be" have the same meaning, just in different tenses. Assuming tense alone does not change the structure, they should both use who. Moreover, if be is here a linking verb, it may not be correct to assume it can be transitive. Only a transitive verb should need an object pronoun such as whom. For example, in "He must decide whom to marry", marry is a transitive verb taking whom as an object.

On the other hand, it appears that who/whom here is in the dative case, or the case of an indirect object. Generally speaking, indirect objects are always supposed to be in object form. One of the key features of indirect objects is that they can be omitted while keeping the sentence fully grammatical: "He must decide whom to be" -> "He must decide to be".

  • 1
    The infinitive (to be) is not a tense, since it is, in both name and definition, non-finite.
    – Anonym
    Dec 16, 2015 at 5:50
  • Strictly speaking, your point may be correct about an infinitive not being in an official tense, but for practical purposes, does it not represent the unspecific tense? For example, on a multiple choice exam, is the "None of the above" option not still an answer? It may not be specific, but choosing this option is certainly different than choosing nothing.
    – Michael
    Dec 16, 2015 at 17:34

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