οἱ δὲ ἰδόντες αὐτὸν περιπατοῦντα ἐπὶ τῆς θαλάσσης ἔδοξαν φάντασμα εἶναι, καὶ ἀνέκραξαν·

1. οἱ
   the
2. δὲ
   but
   and
3. ἰδόντες
   having seen
4. αὐτὸν
   him
5. περιπατοῦντα
   walking
6. ἐπὶ
   upon
7. τῆς
   of the
   the
8. θαλάσσης
   sea
9. ἔδοξαν
   seemed
   they seemed
10. φάντασμα
    apparition
    phantom, appearance
11. εἶναι
    to be
12.  
    ,
     
13. καὶ
    and
14. ἀνέκραξαν
    they cried out
    they cried
15.  
    ·
     

But when they saw him walking on the sea, they thought it was an apparition and cried out.