The given sentence is: Although Jennifer was tired, she still had enough energy to run one more lap.
The break downs are as follow:
Person: THIRD PERSON.
Pronouns are divided into three grammatical person: first, second and third person. The third person refers to the one spoken about. In the sentence given in this question, Jennifer is been spoken about.
Number: SINGULAR [SHE]
A grammatical number can be singular or plural. It is singular if the pronoun used is referring to only one person [e.g: she, he, it, etc]; it is plural if the pronoun used is referring to more than one person [e.g: we, they,etc].
Gender: [FEMININE: SHE].
The person that is been talked about in the sentence is a female.
CASE: SUBJECTIVE CASE.
