Our assignment took the entire semester, because we were to pay attention to speech (or television shows, movies, books, whatever) and find examples of structural ambiguity, then turn in our best examples (I want to say it was 50, but it might have been fewer). You can't come up with 50 good examples off the top of your head in the last three days of a semester. This really was something you had to be thinking about all the time and jotting down as you went.
A couple of examples I remember from class:
Using the word "little" in front of a word that could be either an adjective or a noun. Since "little" can mean both "small" and "somewhat," you end up with structural ambiguity:
It was a little antique.
In that sentence, we can't know whether we're looking at a small antique item or something that's marginally antique.
Out of context, there is no way to tell: structural ambiguity!
My favorite example from class was using a word that can be both an adjective and a verb at the end of the sentence. The resulting ambiguity was awesome:
The peasants are revolting.
So . . . either we have a revolution on our hands, or man, those poor folks really need a bath!
In daily life, we don't usually have a problem with structural ambiguity, because the sentences that could lead to confusion are within a context that clarify what we mean. We know whether we're discussing an antique chair (or a tiny little antique thimble or an early computer that's only kinda antique).
Outside of context, however, you can have all kinds of fun. This is a tool that sitcom writers use all the time for laughs: they have a character overhear something out of context, something with structural ambiguity, and the person interprets it totally wrong. The audience knows both meanings, including the correct one, and we get a big laugh, particularly if the misunderstanding draws the conflict on.
For me, there's a song I cannot hear without thinking of its structural ambiguity. I know full well what the song means, but it still drives me crazy.
The lyrics say:
I can see clearly now the rain is gone.
Now that the rain has passed, which was blurring my eyesight, my vision has cleared up.
My vision is all clear now, and as a result, I can detect that the rain is gone.
The difference is subtle--did the rain cause the vision to clear up, or is the speaker simply stating the facts that their vision is clear where it wasn't before and that now it's clear, they can tell the rain is gone?
I know which the song means, but it still makes me nuts, because my obnoxious brain can't hear the song without thinking of both meanings.
(Thanks, Dr. Oaks. I 'preciate that.)