John 4:24

πνεῦμα ὁ θεός, καὶ τοὺς προσκυνοῦντας ἐν πνεύματι καὶ ἀληθείᾳ προσκυνεῖν δεῖ.

Rough Word-by-word:
spirit the God, and the ones who worship in spirit and truth to worship it is necessary.

Smooth Translation:
God is spirit, and [for] the ones who worship it is necessary to worship in spirit and truth.

πνεῦμα noun nominative singular neuter "spirit" (Note the predicate position here. This is a predicate nominative.)

ὁ definite article nominative singular masculine "the"

θεός proper noun nominative singular masculine "God" (This is the subject. Note the article here but not with πνεῦμα. The anarthrous construction indicates John is saying not that God equals spirit, but that God is spirit.)

καὶ conjunction "and"

τοὺς definite article accusative plural masculine "the"

προσκυνοῦντας present active participle accusative plural masculine from προσκυνέω (I worship) "ones worshiping/ones who worship"

ἐν dative preposition "in"

πνεύματι noun dative singular neuter "spirit"

καὶ conjunction "and"

ἀληθείᾳ noun dative singular feminine "truth"

προσκυνεῖν verb present active infinitive from προσκυνέω (I worship) "to worship"

δεῖ verb present active indicative 3rd singular from δεῖ (it is necessary/must) "it is necessary"