si, why, indeed.
si, if.
sí, indeed, certainly, of course, yes; que —, so; — que, certainly, undoubtedly.
sí, himself, herself, itself, one's self.
sido, past part. of ser.
siempre, always, ever; — que, provided that.
sien, f., temple; head.
siendo, pres. part. of ser.
sienta, pres. of sentar.
siente, sientes, pres. of sentir.