John 6:17

Were going

(ηρχοντο). Picturesque imperfect.It was now dark

(σκοτια ηδη εγεγονε). Past perfect active of γινομα. While they were going, "darkness had already come."And Jesus had not yet come to them

(κα ουκ εληλυθε προς αυτους ο Ιησους). Another past perfect active of ερχομα with negative ουπω. Darkness had come, but Jesus had not come, while they were going over the sea. The tenses in these verses are very graphic.