Fifty of Them

While waiting for the MRT at the Shaw station today, I noticed a tarpaulin poster about the ill effects of smoking and what they do to the smoker's body. One of the captions on the poster read something like "A cigarette has many chemicals. Fifty of it causes illnesses." I don't remember the exact words but I do remember the error: it instead of them and causes instead of cause.

The problem here in one of pronoun referencing. The subject of the sentence is "50 chemicals," which is a plural subject. A plural subject needs a plural pronoun; after all, the pronoun refers to the subject. If the subject is plural, the pronoun should be plural.

The second mistake is the use of the singular verb (causes) when the plural verb should have been used. This mistake stems from the wrong use of it. If the pronoun had been plural, then the correct verb would have probably followed.

Here's the corrected caption: "A cigarette has many chemicals. Fifty of them cause illnesses."