Be careful with that fire or you'll burn yourself.
pronoun You (singular); used emphatically, especially to indicate exclusiveness of the referent's participation in the predicate, i.e., that no one else is involved.
You yourself know that what you wrote was wrong.
pronoun You (singular); even when "you" has not been used previously; see usage notes.
I spoke with yourself last in February.
pronoun Oneself.
These days you have to watch yourself in the center of the city.