John 2:23

Ὡς δὲ ἦν ἐν τοῖς Ἱεροσολύμοις ἐν τῷ πάσχα ἐν τῇ ἑορτῇ, πολλοὶ ἐπίστευσαν εἰς τὸ ὄνομα αὐτοῦ, θεωροῦντες αὐτοῦ τὰ σημεῖα ἃ ἐποίει·

Rough Word-by-word:
As and he was in the Jerusalem in the passover in the feast, many they believed in the name of him, when they saw of him the signs which he was doing.

Smooth Translation:
And as he was in Jerusalem in the Passover feast, many believed in his name, when they saw the signs which he was doing.

Notes:
I don't know why Jerusalem is plural. Other occurrences in the New Testament are also plural. Maybe it is just a transliteration of the Hebrew יְרוּשָׁלַםִ , or perhaps it indicates the idea of an old and new part (after the rebuilding post Babylonian captivity). I'm only conjecturing...

It's hard not to take notice of the many believing in his name while he is doing signs in Jerusalem, in the passover, and in the feast.

Ὡς relative pronoun "As"

δὲ post positive conjunction "and/but"

ἦν verb imperfect indicative 3rd singular from εἰμί (I am) "he was"

ἐν dative preposition "in"

τοῖς definite article dative neuter plural "the"

Ἱεροσολύμοις proper noun dative neuter plural "Jerusalem"

ἐν dative preposition "in"

τῷ definite article dative neuter singular "the"

πάσχα noun dative neuter singular "Passover"

ἐν dative preposition "in"

τῇ definite article dative feminine singular "the"

ἑορτῇ noun dative feminine singular "feast"

πολλοὶ adjective nominative masculine plural "many"

ἐπίστευσαν verb aorist active indicative 3rd plural from πιστεύω (I believe) "they believed"

εἰς accusative preposition "in/into"

τὸ definite article accusative neuter singular "the"

ὄνομα noun accusative neuter singular "name"

αὐτοῦ pronoun genitive masculine singular "of him"

θεωροῦντες present active participle nominative masculine plural from θεωρέω (I see/I behold) "when they saw"

αὐτοῦ pronoun genitive masculine singular "of him"

τὰ definite article accusative neuter plural "the"

σημεῖα noun accusative neuter plural "signs"

ἃ relative pronoun "which"

ἐποίει verb imperfect active indicative 3rd singular from ποιέω (I do/I make) "he was doing"