In linguistic text, ambiguity is the possibility of two quite different meanings with exactly the same wording. Identifying and correcting ambiguity can sharpen your writing and copy-editing skills. Ambiguity occurs in all languages, but English is particularly prone. Unlike other Germanic languages, much of its morphological grammar was stripped away more than a thousand years ago; so the way modern English phrases and clauses relate to each other is complicated, and many words can function in several ways.
The same word, for example, can often serve as a noun or a verb ("Union demands increased unemployment", "we saw her duck"), and many words have multiple meanings ("prostitutes appeal to the pope", "the children made tasty meals"). There can be grammatical ambiguity, beyond the scope of individual words: "we asked how old Joe was" (how old was he? or how was he doing?); and "The chicken is ready to eat" (ready for us to eat it, or ready to eat its feed in the yard?).
English does have unfortunate engineering faults, such as the idiomatic ambiguity in "I can't recommend this dish too highly";1 and let's not forget words that—embarrassingly—can convey starkly opposite meanings ("in this city they sanction drug-dealing"; "she secretly replaced the cup she had chipped"). Hyphens (and en dashes) can make a difference ("a senior class teacher" is a class teacher who is senior, but "a senior-class teacher" teaches a senior class; see MOS:HYPHEN). So can commas ("The author thanked her parents, Sinéad O'Connor and President Obama", referring to four rather than two people).
Ambiguity may be removed by changing the word order, the grammar, or the punctuation, or by substituting a word that is unambiguous in the context.
The exercises below are meant to be entertaining. Often the task is a puzzle, and some of the unintended meanings can be amusing. To make it more challenging, ambiguous sentences are mixed randomly with some that are unambiguous: it would be too easy if you knew that every example was ambiguous. Some that are ambiguous would be perfectly fine in a larger context, and some wouldn't; but here, you're asked to consider the examples in isolation. This is a laboratory situation, if you like.
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1Some of the examples in the lead are adapted from a book by Noel Burton-Roberts, from a NYT-affiliated website, and from the Stanford Encyclopedia of Philosophy, all cited below.
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