I vs us

I

• The speaker or writer, referred to as the grammatical object, of a sentence. 

• The speaker or writer, referred to as the grammatical subject, of a sentence. 

• The ninth letter of the English alphabet, called i and written in the Latin script. 

• Interstate. 

• The ego. 

us

• Me and at least one other person; the objective case of we. 

• Me. 

• Our. 

• Me (in all contexts). 

• The speakers/writers, or the speaker/writer and at least one other person.