Parsing  Scroll down, or click on linked line numbers.
( Line1 ) ( Line 2 ) ( Line3 ) ( Line 4 )

Line 1
Furi
   masculine singular vocative

et
   conjunction

Aureli
   masculine singular vocative

comites
   masculine plural vocative in apposition to Furus and Aurelus

Catulli
   masculine singular genitive

Line 2
sive
   conjunction

in
   preposition governing extremos

extremos
   adjective masculine plural accusative modifying Indos

penetrabit
   3rd person singular future indicative active Catullus is the understood subject

Indos
   masculine accusative plural object of preposition in

Line 3
litus
    masculine nominative singular subject of tunditur

ut
    adv

longe
    adv

resonante
    feminine singular ablative with unda

Eoa
    feminine singular ablative with unda

Line 4
tunditur
   3rd person singular present indicative passive

unda
   feminine singular ablative