Co-ordinating units of writing must all be of the same grammatical kind. This is what is referred to as preserving parallel structure. For instance, nouns must match with nouns, adjectives with ...

“Plop plop, fizz fizz, oh what a relief it is.” You might have thought that only the pill that goes with that jingle creates relief. But science suggests the jingle’s wording itself elicits relief.

“Plop plop, fizz fizz, oh what a relief it is.” You might have thought that only the pill that goes with that jingle creates relief. But science suggests the jingle’s wording itself elicits relief.