Be a comma chameleon
Are you a comma-crazy writer who sprinkles commas throughout your sentences so you hopefully seem clever? Or are you a comma-phobic writer who uses ‘minimal punctuation’ and omits the comma altogether? Or are you a ‘comma, comma, comma, comma, comma chameleon’ who can flexibly tailor your comma usage so you convey your meaning as quickly as possible?
Let’s study four problematic combinations of words:
‘Are you eating boys?’
This direct question concludes with a form of address, ‘boys’, which should have a comma before it; otherwise, our readers might well take ‘boys’ to be the direct object of the transitive verb ‘eating’.
A transitive verb ‘carries the action across’ from the grammatical subject, in this case ‘you’, to the direct object, in this case ‘boys’, rather than a noun you’d expect to be the object, such as ‘food’.
‘As Mum knitted the dog ate his dinner.’
The dependent clause, ‘As mum knitted’, should have a comma after it so it’s separated from the independent clause, ‘the dog ate his dinner.’
An independent clause contains a ‘finite’ (finished, complete) verb (‘ate’) and can stand on its own as a complete sentence.
A dependent clause also contains a finite verb (‘knitted’) but can’t stand on its own.
Because ‘the dog’ isn’t the direct object of the verb ‘knitted’, and because ‘knitted’ is an intransitive verb, the verb should have a comma after it.
We could instead transpose the two clauses and omit the comma: ‘The dog ate his dinner as Mum knitted.’
‘Don’t fool yourself, speed kills.’
This sentence is actually two sentences, or independent clauses: ‘Don’t fool yourself’, which is a command, and ‘Speed kills’, which is a statement. The comma is merely a little pause and is too weak to conclude the first independent clause, because another independent clause follows.
We could instead use a full stop (.), a semi-colon (;), a colon (:), a textual dash ( – ), an exclamation mark (!) or an ellipsis (…). Alternatively, we could parenthesise the second independent clause and write, ‘Don’t fool yourself (speed kills).’
Also, unlike ‘boys’ in sentence 1, ‘speed kills’ isn’t a form of address, so it shouldn’t have a comma before it. Never place a comma between two standalone sentences or independent clauses.
‘The Disney movie Shark Tale, starred a vegetarian shark!’
In the active voice, the grammatical subject of the sentence or clause is the person, animal, thing or idea who or that does something, has something or is something.
In the passive voice, the grammatical subject of the sentence or clause is the person, animal, thing or idea who or that passively ‘receives’ the action, and is also the direct object of the transitive verb.
The finite verb is the ‘action’, ‘doing’ ‘being’ or ‘having’ word.
The predicate is the finite verb plus everything else, that is, everything other than the grammatical subject.
In the example sentence, which is an exclamation, the grammatical subject is ‘The Disney movie Shark Tale’, the finite verb is ‘starred’ and the predicate is ‘starred a vegetarian shark!’. The movie title ‘Shark Tale’ is an essential element, that is, essential information about ‘The Disney movie’.
We can never use a comma to separate the grammatical subject from the verb/s, because the subject ‘does’ the action, doing, being or having via the verb/s and is therefore directly linked to the verb/s.
To be a comma chameleon, all we have to do is change our ‘comma mindset’ and use ‘comma-sense’!