Read the sentence. no one could believe their luck when the owner of the restaurant offered free dessert to all. what is the agreement error in this sentence? the pronoun “their” does not match its antecedent in number. the pronoun “their” does not match its antecedent in person. the pronoun “their” does not match its antecedent in case or number. the pronoun “their” does not match its antecedent in number or person.

The answer to your question would be that the agreement error in the sentence is the following one: The pronoun "their" does not match its antecedent in number, which is "no one" (singular).

The sentence above is a clear example of the use of singular they. Singular they is the use in English of the pronoun they or any of its derivative forms (them, their, theirs, and themselves) as a gender-neutral singular pronoun. This use of the pronoun they typically occurs with an unspecified antecedent, such as "No one".

they insisted that there was not enough time to learn everything.  

explanation:

if they were going to steal the answers that is simply because they insisted that there was not enough time to learn everything.  

what is the question ?