Final answer:
The correct pronoun to complete the sentence about Jane is "she", as it refers to the subject 'Jane' and is in the subjective case, appropriate for the subject of the verb 'was going'. Correct pronoun case selection is critical for clear communication in English grammar.
Step-by-step explanation:
The correct pronoun to complete the sentence "Jane did not tell her colleagues where she was going for lunch." is she. The pronoun she is used here because it's referring back to Jane, who is the subject of the sentence. It is important to choose the correct pronoun case when constructing a sentence.
In this instance, she is the subjective case pronoun, appropriate for the subject of the verb 'was going'. While addressing the same concept in compound structures or after prepositions like 'than' or 'as', the pronoun's case would indicate what has been left out from the sentence.
Pronoun case selection is a crucial element in ensuring that sentences convey the correct meaning. As a general rule, subjective case pronouns are used when the pronoun is the subject of the verb, while objective case pronouns are used for the object of the verb or preposition. The sentence provided has its subject ('Jane') doing the action of 'was going', hence the subjective case pronoun she is the best fit.