John 3:16

οὕτως γὰρ ἠγάπησεν ὁ θεὸς τὸν κόσμον, ὥστε τὸν υἱὸν τὸν μονογενῆ ἔδωκεν, ἵνα πᾶς ὁ πιστεύων εἰς αὐτὸν μὴ ἀπόληται ἀλλ' ἔχῃ ζωὴν αἰώνιον.

Rough Word-by-word:
As this for loved the God the world, so that the son the one born he gave, that every the one believing into him not may perish but he may have life eternal.

Smooth Translation:
For so loved God the world, that he gave the one born son, that every one believing in him may not perish but may have eternal life.

Notes:
It is hard to give a translation other than the familiar one here because this is such a well known verse.

There are theological implications for how we translate μονογενῆ so I chose to use a literal rendering of the compounds. This may be an idiomatic word. I really don't know. The gloss in the UBS 4 lexicon is "only, unique."

The οὕτως ἠγάπησεν "so loved" seems to indicate the how of God's love, not necessarily the degree, even though the degree is extreme and is certainly implied.

οὕτως compound adverb "as this/so"

γὰρ post positive conjunction "for"

ἠγάπησεν verb aorist active indicative 3rd singular from ἀγαπάω (I love) "he loved"

ὁ definite article nominative masculine singular "the"

θεὸς proper noun nominative masculine singular "God"

τὸν definite article accusative masculine singular "the"

κόσμον noun accusative masculine singular "world"

ὥστε conjunction "so that"

τὸν definite article accusative masculine singular "the"

υἱὸν noun accusative masculine singular "son"

τὸν definite article accusative masculine singular "the"

μονογενῆ substantive adjective accusative masculine singular "one born/only/unique"

ἔδωκεν verb aorist active indicative 3rd singular from δίδωμι (I give) "he gave"

ἵνα conjunction signaling the subjunctive "that"

πᾶς adjective nominative masculine singular "all/every"

ὁ definite article nominative masculine singular "the"

πιστεύων present active participle nominative masculine singular from πιστεύω (I believe) "one believing"

εἰς accusative preposition "into"

αὐτὸν pronoun accusative masculine singular "him"

μὴ adverb of negation "not"

ἀπόληται verb aorist middle subjunctive 3rd singular from ἀπόλλυμι (I perish) "he may perish"

ἀλλ' strong adversative conjunction "but"

ἔχῃ verb present active subjunctive 3rd singular from ἔχω (I have) "he may have"

ζωὴν noun accusative feminine singular "life"

αἰώνιον adjective accusative feminine singular "eternal"