John 1:36

καὶ ἐμβλέψας τῷ Ἰησοῦ περιπατοῦντι λέγει· ἴδε ὁ ἀμνὸς τοῦ θεοῦ.

and having looked on the Jesus as he is walking he says, "Look the lamb of the God."

καὶ conjunction "and"

ἐμβλέψας aorist active participle nominative masculine singular from ἐμβλέπω (I look on/I see) "having looked on" (Note: The aorist participle in the predicate position reflects action taking place before the action of the main verb of the clause which in this case is λέγει, present active indicative)

τῷ definite article dative masculine singular "the"

Ἰησοῦ proper noun dative masculine singular "Jesus"

περιπατοῦντι present active participle dative masculine singular from περιπατέω (I walk) "as he is walking" (Note: The present participle in the predicate position reflects action taking place at the same time as the action of the main verb. It is predicate here, but notice the dative case. It is as Jesus is walking, not as John is walking.)

λέγει verb present active indicative 3rd singular from λέγω (I say) "he says" (Note: The apostle John is using historic present both here and with the preceding participle so a smooth English translation will reflect that)

ἴδε verb present active imperative 2nd singular from εἴδω (I see) "See/Look/Behold"

ὁ definite article nominative masculine singular "the"

ἀμνὸς noun nominative masculine singular "lamb"

τοῦ definite article genitive masculine singular "the"

θεοῦ noun genitive masculine singular "of God"

Rough Word-by-word:
and having looked on the Jesus as he is walking he says see/look/behold the lamb the of God

Smooth Translation:
and having looked on Jesus walking, he said, "Look, the lamb of God."