What is a Subject Complement?
A subject complement is a word or phrase that follows a linking verb such as ‘is’ or ‘seems’. It isn’t the object of a verb but a noun or a pronoun which linked to the subject by a verb. The grammar rule is that subject complements should be in the same case as the subject they are linked to, which is, the subjective case. However, It’s me and It’s us break the rule, because ‘It’s I’ and ‘It’s we’ seem impossibly unnatural. There are sentences in which obeying the rule is not idiomatically objectionable. In ‘It was I who broke the news’, the subjective ‘who’ seems to make ‘I’ preferable even though in principle there need be no agreement in case between a pronoun and its antecedent. ‘It’s him’ and ‘It’s her’ cannot be similarly defended, because ‘It’s he’ and ‘It’s she’, although perhaps unnatural, are not unusual; most careful speakers and writers do use them. ‘It’s them’ is perhaps more often defensible, because ‘It’s they’ is more than “slightly unnatural”.
The following examples seem fine to me ‘That was he attending all the meetings and reporting back to the committee’ likewise ‘That was she attending all the meetings…’ or ‘That was they attending all the meetings…’ even though they seem to be contrary to common usage of “him”, “her” and “them” nonetheless are correct. It we reverse the sentence “him”, “her” “them” would not make any sense here. Let’s consider some other examples, ‘That was him whom I came across on my way to the meeting room.’ Or ‘That was her whom I will be coaching this month.’ In these sentences the pronouns should be in objective case. We can as well omit “who” and “whom”, i.e. ‘That was him I came across…’, ‘That was her I will be coaching…’
Pronouns as Part of Compound Objects
‘Our parents send John and I to Europe every summer.’ is an embarrassing error. Some of us go too far and give up the objective case in compound objects, even though very few of us would fail to use the objective case for a pronoun standing alone as object, i.e. ‘Our parents sent I to Europe…’ is an obvious error in English. Here the grammar rule is the following: pronouns which are part of compound objects should be in objective case – me, him, her, us, you, them should be used, – “Our parents send John and me to Europe every summer” is correct.
Pronouns as Objects of Gerunds, Infinitives and Participles
‘I hate greeting him’, or ‘I hate to greet him.’ ‘The man greeting him must be his son.’ The objects of verbals, i.e. gerunds, infinitives, and participles, are always in the objective case. The subject of a gerund should usually be in the possessive case, the subject of an infinitive should be in the objective case, as in ‘I want him to greet me.’, and the subject of a participle can be either in subjective or objective case, depending on its role in the sentence, but the objects of gerunds, infinitives, and participles are always in objective case.
Pronouns as Objects of Prepositions
‘Everyone but he left’ is an error. In this case the word “but” is not a conjunction but a preposition, i.e. ‘Everyone left except him’. In the above sentence “but” has the same meaning as the preposition “except”. In the example ‘She left but he didn’t’ “but” is a conjunction. Accordingly, if “but” is a preposition as in the example ‘Everyone but him left’ and ‘Everyone left but me’, its object must be in the objective case. It is not the case with ‘Everyone left but he didn’t leave’, here there is a logical contradiction, i.e. if he didn’t leave, then it is false to say that everyone left, nonetheless the structure of the sentence is grammatically correct.
‘Like’ as a Conjunction
In spoken English it is very common to use ‘like’ as a conjunction, e.g. ‘Don’t act like you don’t know that he is having an affair with that blonde’, or ‘You are staring at me like you see a ghost’ – these examples are not correct. The error is usually made not because of ignorance of English grammar rules but because of a misunderstanding of the word ‘like’, which should not be used as a conjunction to mean ‘as’ or ‘as if’. In informal English, ‘like’ is sometimes used as a conjunction instead of ‘as’. This is very common in American English, e.g. Nobody understands me like you do (informal)’, i.e. ‘Nobody understands me as you do’ (formal). ‘Like’ is used after verbs ‘seem’, ‘look’, ‘sound’, ‘smell’, ‘taste’ and ‘feel’, e.g. ‘He seemed like such a nice person when I first met him’, or ‘It looks like an unusually warm weather for this time of the year’. ‘As’ is not usually possible in this case.