Mrs. Kanwal is ___ Principal of this school.

Answer: Mrs. Kanwal is the principal of this school.

Explanation: Use the definite article 'the' because the sentence refers to a specific person who holds the role in that particular school.

• The definite article 'the' is used before nouns when both speaker and listener know which person or thing is meant.

• The indefinite articles 'a' and 'an' are used for non-specific singular nouns. Use 'an' before vowel sounds (for example, 'an hour').

• In this sentence, the principal is a specific person at this school, so 'the' is correct.

Note: When 'principal' follows a verb as a common noun it is lowercase: 'principal'. Capitalize it when used as a title before a name (for example, 'Principal Kanwal').