How to Identify the Subject of a Sentence
You probably think you know what a subject and a verb is, since you can't have a sentence without at least one of each. But can you pick them out of a lineup? Let's try - in the style of a 1940s crime noir drama.
The stubborn case had busted wide open again.
When looking for the subject in a sentence, look for the verb first. Remember that a verb is a word that either helps a subject perform an action (ran, drank, fights, swims) or shows a state of being (is, was, are, were) that connects the subject to the action. In the sentence here, the main verb is 'busted.' What is the thing being busted? The case.
When we talk about subjects we'll talk about simple subjects, complete subjects, and compound subjects.
Simple Subject
A simple subject is just the subject without any of its modifiers (adjectives, adverbs - that is, any explanatory details). So the simple subject here is 'case,' while the complete subject contains all of the verb's descriptors - that would be 'stubborn case.' Let's try another example.
The husband wasn't dead.
Put 'who' and 'what' in front of the verb to see if you can find the subject. Here, the verb is a linking verb - 'was.' Linking verbs link the subject ('The husband') to the subject's state of being. Who was not dead? The husband. That's your subject.
Let's keep going.
He was walking down Royal Street in a three-piece suit!
Here we have a past participle form in verb phrase 'was walking.' So again you have 'was,' and we know he 'was walking.' But you can use the same formula. Who was walking? 'He' was. So the pronoun 'he' is the subject of the sentence. We'll talk more about pronouns a little bit later.
Multiple Subjects and Verbs in a Sentence
Personal Pronouns
Back at my desk, I poured myself a rattlesnake, grabbed it by the tail, and gulped it down.
When you see a personal pronoun - 'I,' 'you,' 'he,' 'she,' 'it,' 'we,' and 'they' - a verb will follow. In this case, the verb that follows is 'poured,' followed later by 'grabbed' and 'gulped.'
One exception to this rule is when the pronoun refers to the earlier subject. Take this example:
The lady led him on a wild goose chase, didn't she?
Using the same formula as before, we see that 'led' is the main verb. What 'led'? 'The lady.' No verb follows 'she' in this special case because its function is to ask a question related to the clause preceding it. That is, 'The lady led him on a wild goose chase.' The 'she' is 'the lady,' so it doesn't need a verb to follow after it. But in general, when you see a personal pronoun, a verb will follow, and that personal pronoun is the subject of the sentence.
Passive Constructions: Where's the Subject?
In a passive sentence, the subject does not 'do' the action; the action instead happens to the subject. Let's return to our floundering P.I.
That, or the death had been faked by the husband for some more mysterious reason.
You're right if you think that 'death' is the subject here. After all, what was faked? The death 'had been faked.'
Hidden (Implied) Subjects
In the case of a command - that is, when someone is telling you to do something - there won't be any clear subject in the sentence. Instead, the subject is implied - the subject is you!
So the sentence, Wait! Don't be a fool. is really, (You) Wait! Don't (you) be a fool. Keep an eye out for those implied subjects, especially in a sentence where it's not exactly clear where the subject is. The same thing is true of passive sentences.