Questions that look like the following appear on the English portion of virtually every ACT:

What do you get when you cross a chicken with an apple? A daffodil with rice? A flounder with a tomato? These aren’t jokes, waiting for a punch line.

B. jokes waiting
C. jokes, waiting
D. jokes, waiting,

Although this appears to be a question about commas, it’s actually about something else entirely: relative clauses. Now, the term “relative clause” is one that I avoid whenever possible; it tends to make people a little bit nervous. It also sounds kind of icky and grammatical, the sort of thing that’s so absurdly complicated that it makes you want to throw up your hands in utter defeat before you’ve even started to try to understand what it is.

Here’s the thing, though: relative clauses aren’t actually that hard. And in order to be certain about these questions — which can be among the trickiest English questions on the ACT — it really helps to understand the basic grammar behind them.

Relative pronouns are words like which, who(se), and that. They are frequently used to connect two sentences that would sound stiff and unnecessarily repetitive when written separately.


Without relative pronoun: I saw a man. The man was eating a hamburger.

With relative pronoun: I saw a man who was eating a hamburger.


Without relative pronoun: This is the book. I read the book yesterday.

With relative pronoun: This is the book that I read yesterday.

It is also possible to join the sentences and create a relative clause without using a relative pronoun. For example:

Correct: I saw a man who was eating a hamburger.


Correct: This is the book that I read yesterday.

When you get rid of the relative pronoun, however, you do not ever need to replace it with a comma — but this is exactly what the ACT does. And in the vast majority of instances, the pronoun in question will be that:

Correct: This is the book that I read yesterday

Correct: This is the book I read yesterday

Incorrect: This is the book, I read yesterday.

Which brings us back to the original question. The underlined portion of the sentence is in fact a relative clause. It could have also been written this way:

These aren’t jokes that are waiting for a punch line.

But since the relative pronoun that doesn’t appear in the sentence, no comma is necessary. The answer is therefore B (“These aren’t jokes waiting for a punchline.”)

Recognizing these questions can take a little bit of thought — they’re easy to overlook if you’re not expecting them to be there. But since there’s at least one on pretty much every single test, learning to recognize them can get you a guaranteed point or two.