Εἰ μὴ γὰρ ἐβραδύναμεν, ἤδη ἂν ὑπεστρέψαμεν δίς.

1. Εἰ
   If
2. μὴ
   not
3. γὰρ
   for
4. ἐβραδύναμεν
   we had delayed
5.  
   ,
    
6. ἤδη
   already
7. ἂν
   would
8. ὑπεστρέψαμεν
   we would have returned
   we have returned
9. δίς
   twice
10.  
    .
     

If we had not delayed, we would have already returned twice.