ἀπ᾽ ἄρτι λέγω ὑμῖν πρὸ τοῦ γενέσθαι, ἵνα ὅταν γένηται πιστεύσητε ὅτι ἐγώ εἰμι.

1. ἀπ᾽
   from
2. ἄρτι
   just now
3. λέγω
   i say
4. ὑμῖν
   to you
5. πρὸ
   before
6. τοῦ
   of the
   the
7. γενέσθαι
   to become
8.  
   ,
    
9. ἵνα
   so that
10. ὅταν
    whenever
    when
11. γένηται
    becomes
12. πιστεύσητε
    you may believe
    you will believe, you believe
13. ὅτι
    that
    because
14. ἐγώ
    i
15. εἰμι
    am
    i am
16.  
    .
     

From now on I tell you before it happens, so that when it happens you may believe that I am.