Final answer:
The personal pronoun 'I' is the best choice to convey innocence and determination in a speech, as it asserts personal conviction and involves the audience in the speaker's perspective.
Step-by-step explanation:
To write a short speech that conveys innocence and determination, the personal pronoun that best supports a character's determination is 'I'. This pronoun falls into the category of subjective case pronouns, which are used when the pronoun is the subject of a verb, as in 'I am innocent.' The use of 'I' provides a direct and assertive tone that implies personal involvement and conviction in the statement made, which is essential when conveying innocence and determination.
Moreover, the use of the first-person narrative allows the speaker to express personal experiences and emotions, drawing the audience into their perspective and fostering a connection that can help to assert their innocence. Phrases using 'I' in such a speech might include 'I stand before you with a clear conscience' or 'I have always acted with integrity.'