What is the difference between se and sé?

These monosyllables are distinguished graphically by the presence of the acute accent on the vowel e. Se is a conjunction used in hypothetical clauses: Se fosse venuto ieri, mi avrebbe visto. Sé is the reflexive pronoun for the third-person singular: Pensa solo a sé. When sé is followed by the demonstrative adjective 'stesso' the reflecive pronoun can be written without the accent, since it cannot be confused with the conditional conjuction: Pensa solo a se stesso/Pensa solo a sé stesso.