Unintentional Ambiguity

Ambiguity can be effective in poetry and lies, but for good communication, you want to avoid it. Your reader ought to have no doubt about what you mean.

So here’s another way to be unintentionally ambiguous. Watch out for it.

Prepositional phrases normally come right after whatever they modify. This leads to ambiguity if you have two or more prepositional phrases in a row. Does the second phrase modify the first phrase, or do both phrases modify the same word? Sometimes you luck out and both ways make sense. Here’s an example:

“Mail the invoice on the day of shipment to the customer.”

We could decide that the sentence says to mail on the day etc—and mail it to the customer. But the sentence could also be referring to the day the item is shipped to the customer (as opposed to some other place, such as the local shipping terminal). Both ways mean about the same thing, though the emphasis is slightly different. Reversing the phrases is a little better:

“Mail the invoice to the customer on the day of shipment.”

The identity of the customer is not likely to depend on the day of shipment, so our mind makes the leap and attaches the day of shipment to mailing the invoice, even though it has to jump clear across the sentence to do so.

This is a trivial example, but misinterpreting two prepositional phrases in a row can lead to humorous or disastrous interpretations.

Humorous: “Two Sisters Reunited After 18 Years at Checkout Counter.” The grammar is fine, isn’t it? Try this: “Sisters separated for 18 years are reunited at a checkout counter.” No longer funny, but not ambiguous, either.

Can you come up with a serious misunderstanding? Share.