which sentence is missing an antecedent?
1. roberta has left the water on in her bathroom
2. richard has paid his field trip money
3. you must turn in your forms, or it wont happen
4. you should carry your wallet at all times

The correct answer is 3. You must turn in your forms, or it won't happen

Explanation:

In grammar, an antecedent is a subject, pronoun or another type of word or words usually at the beginning of a sentence that gives meaning to another word, phrase or other. This implies the antecedent is a word that precedes or come before another word whose meaning is the same or is linked to the antecedent. For example, in the sentence "I love my sister" the antecedence is "I" as it gives meaning to "my sister" whose meaning depends on the "I" and it is directly connected to it. In the case of "You must turn in your forms, or it won't happen" the antecedent should be the first part of the sentence "you must turn in your forms" but it is followed by "or it won't happen" whose meaning is not connected to the possible antecedent and does not depend on it, because of this, as there is not a relationship between one part and there other there is not an antecedent as in the second part there is no reference of the first one.

answer: do

the 'italicized phrase' is a noun clause that is used as a direct object.