In what ways are each of these expressions structurally ambiguous?

(a) The parents of the bride and groom were waiting outside.

(b) We met an English history teacher.

(c) Flying planes can be dangerous.

(d) The students complained to everyone that they couldn't understand

Answer and explanation:

Structural ambiguity refers to sentences that can be interpreted in more than just one way because of their construction. Structural ambiguity is also called syntactic ambiguity. Let's analyze each sentence:

(a) The parents of the bride and groom were waiting outside.

We are not sure who was waiting outside. We can interpret it as meaning that the bride's parents and the groom's parents were all waiting outside. But we can also understand that the bride's parents were waiting outside with the groom.

(b) We met an English history teacher.

Who did we meet? A history teacher who happens to have been born in England? Or a teacher who teaches English history?

(c) Flying planes can be dangerous.

We know something related to planes is dangerous. If we see "flying" as a verb, then the action of flying a plane is dangerous. If we see "flying" functioning as an adjective, then planes that fly, that are up in the air, are dangerous.

(d) The students complained to everyone that they couldn't understand.

We know the students complained to everyone. What we don't know is if the students complained to everyone because they couldn't understand something, or if they complained to the very people who were unclear, that is, to everyone that was misunderstood by the students.

As we can see, all the sentences above are structurally ambiguous since the disposition of the words allow for more than one interpretation of meaning.