_he says_.=

Wrong: The man whom they believed was the cause of the trouble
left the country. [_They believed_ is parenthetical, and the
subject of _was_ is _who_.]

Right: The man who they believed was the cause of the trouble
left the country.

Wrong: Whom do you suppose made us a visit?

Right: Who do you suppose made us a visit?

=Guard against the improper attraction of _who_ or _whoever_ into the
objective case by a preceding verb or preposition.=

Wrong: Punish whomever is guilty. [The pronoun is the subject
of _is_. The object of _punish_ is the entire clause _whoever
is guilty_.]

Right: Punish whoever is guilty.

Wrong: The mystery as to whom had rendered him this service
remained. [The pronoun is the subject of _had rendered_. The
object of the preposition is the entire clause _who had
rendered him this service_.]

Right: The mystery as to who had rendered him this service
remained.

=c. The predicate complement of the verb _to be_ (in any of its forms,
_is_, _was_, _were_, _be_, etc.) is in the nominative case.= _To be_
never takes an object, because it does not express action.

Wrong: Was it her? Was it them? It is me.

Right: Was it she? Was it they? Is it I.

Wrong: The happiest people there were him and his mother.

Right: The happiest people there were he and his mother.

=d. The object of a preposition or a verb is in the objective case.=

Wrong: Some of we fellows went fishing.

Right: Some of us fellows went fishing.

Wrong: That seems incredible to you and I.

Right: That seems incredible to you and me.

Wrong: Who did they detect?

Right: Whom did they detect?

=e. The "assumed" subject of an infinitive is in the objective case.=

Right: I wanted him to go. [_Him to go_ is the group object of
the verb _wanted_. _To go_, being an infinitive, cannot assert
an action, and consequently cannot take a subject. But _to go_
implies that something is at least capable of action. _Him_ is
the latent or assumed subject of the action implied in _to
go_.]

Right: _Whom_ do you wish _to be_ your leader? [_Whom_ is the
assumed subject of the infinitive _to be_.]

=f. A noun or pronoun used to express possession is in the possessive
case.= Do not omit the apostrophe (See 97) from nouns, or from the
pronouns _o