During a visit to the Edinburgh Zoo, Geoff Pullum figures out the source of a remarkable piece of erroneous grammar advice that mistakes verbless clausal dangling modifiers for passive clauses.

Clarity in writing includes form, not just words.

When he was teaching journalism, he found that the dangling modifier was the most common grammar mistake he encountered. Fortunately, most danglers are easily fixed.

Sheets don’t sleep. That’s why this sentence is a classic example of a dangling participle. A dangling participle is just one type of dangling modifier or, more simply, dangler.

The most common kind of dangling modifier is a dangling participle, as at the beginning of this column. Participles are those verb forms that end in -ing in the present tense, and usually in -ed ...

One mistake many make in this regard is courting dangling modifiers. These are modifiers so loosely put in sentences that you do not know which parts of the structures they are working with.

My friend Peter Page builds high-rises. He knows that if he were to put a beam in the wrong place, the whole thing could come down. In a much less dramatic, costly and dangerous way, a misplaced ...