I vs yourself

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. 

yourself

• You (singular); used emphatically, especially to indicate exclusiveness of the referent's participation in the predicate, i.e., that no one else is involved. 

• Your own self (singular).