How is "Dogs dogs fight fight" grammatical?

I got this from https://youtu.be/yj-qmd4Cb78?t=1555 at 25:55

Can you help me make sense of this sentence?

The presenter’s explanation "Dogs that other dogs fight, themselves fight." didn’t clarify it for me.

Solution 1:

I think the repetition makes it confusing. It might be helpful if you changed some of the words and worked your way back to the original.

Men [whom] dogs bite fight.

This means "those men who are bitten by dogs tend, habitually, to fight." I suspect this is not very confusing to you.

Now imagine the subject is dogs.

Dogs dogs bite fight.

Or, those dogs who are bitten by [other] dogs tend, habitually, to fight.

That brings us back to:

Dogs dogs fight fight.

Or, those dogs whom other dogs fight, themselves fight.

That is not very different from the explanation you said you did not understand, but hopefully by seeing the same grammar in a less exotic statement you can see how the construction is the same.

That said, this is one of those "only technically" grammatical sentences. In reality, nobody would use this sentence, because it sounds bad and is not easily understood.

Solution 2:

This is called "center embedding". Center embedding is a topic of linguistic interest specifically because it's relatively easy to use it to form sentences that are nearly incomprehensible despite being "grammatical" in terms of grammar rules.

Usually sentences with only one level of center embedding are relatively easy to understand, but this example uses two pairs of identical words and has a fairly contrived meaning, which makes it harder to understand.

Other previous questions on similar sentences:

• Is "women men girls love meet die" a valid sentence?

• What does "Ducks ducks duck duck" mean?

Solution 3:

The dogs, you know, the ones that other dogs fight, they fight back, they do.

Solution 4:

This is much easier if rewritten with punctuation and an explicit use of conjunction.

Dogs, (that) dogs fight, fight.