For reference only. Please do not copy this translation verbatim.
[Brackets] indicate a word that is supplied
420. Whom* Pallas seeks, having prayed before in this way: (*"whom" or "that man". It depends on whether you care more about being literal or not being awkward.)
421. "Now give, father Tiber, fortune and a way through
422. the chest of harsh Halaesus, to my sword, which I balance, ready to be thrown.
423. Your oak tree will have these arms and the spoils of the man."
424. A god heard those [words]; while Helaesus protected Imaon,
425. he gives his unlucky, unarmed chest to the Arcadian weapon.
426. But Lausus, a huge part of the war, does not desert the lines
427. from so great a terrified slaughter of a man: he first kills
428. opposed Abas, both a knot and a delay* of the fight. (*i.e. Abas is holding Lausus up; he is in the way of his fight.)
429. The offspring of Arcadia is lain low; the Etruscans and you, Trojans,
430. O bodies undestroyed by the Greeks, are lain low.
431. The lines join battle with both equal leaders and strength;
432. lines of the outside* thicken and the crowd does not allow (*of the outside = extremi.)
433. weapons and hands to be moved*. From here, Pallas pursues and urges; (*it is so crowded that you can't even engage in combat, whether hand-to-hand or with weapons.)
434. from here, opposite, Lausus [pursues and urges], and their age does not differ much,
435. [they are] remarkable in form*, but Fortune had denied** (*forma = ablative of respect. *had denied = negarat = negaverat)
436. returns into their fatherland to those men*. (*The "i" in "quis" should have a macron on it. "Quis" with a long "i" is an alternate form of "quibus". You could either make this "to those men" or "to which men". Choose whichever you're more comfortable with. This line means that Lausus and Pallas are going to die in battle and will never return home alive.)
437. However, the ruler of great Olympus did not allow* them themselves to join battle among themselves;(*passus = passus est. This line means that Pallas and Lausus will never confront each other personally in battle)
438. soon their fates await them beneath a greater enemy. (An enemy stronger than them will defeat them.)
439. Meanwhile, a nourishing sister* warns Turnus, (*Turnus' sister Juturna.)
440. who cuts the middle of the line with his winged chariot, to approach Lausus*. (Of course Turnus' chariot isn't really winged. It is just going so fast it seems like it. *Lauso = dative with special verb "succedere")
441. As he saw his comrades, [he said]: "[It is] time to stop the fight*, (*pugnae = dat. with special verb "desistere")
442. I alone am carried into Pallas, Pallas is owed to me alone*; (*soli is one of the Naughty Nine adjectives, so it is dative, not genitive.)
443. I would desire [that] his father himself were here as a spectator."
444. He speaks these words, and his comrades withdrew from the ordered plain*. (*from here on out, assume "aequor" means "plain" rather than "sea" because the fighting is taking place on land.)
445. But at the departure* of the Rutulians, the young man, (*abscessu = the book calls this "circumstance", which is basically like time when.)
446. having marveled at the proud orders, then is stupefied on Turnus and turns
447. his eyes through the whole body and goes over all things from afar* with fierce sight, (*procul can mean "far [off]" or "from afar".)
448. and he goes against the words of the tyrant with such words:
449. "I will be praised now, either with seized spoils of honor
450. or with a marked death; the father is fair to each* fate. (*The adjective "uterque" comes from "uter", one of the Naughty Nine adjectives, so "utrique" is dative, not genitive, and goes with "sorti". Pallas is basically saying that his father will be proud of him, whether he defeats Turnus or is defeated by him.)
451. Raise threats." Having spoken, he proceeds into the middle of the field;
452. for the Arcadians, cold blood goes together into their hearts.
453. Turnus jumped down from his chariot*; a foot traveler, (*The noun biiugi, biiugorum m. pl. means "chariot".)
454. he prepares to go hand-to-hand; and as a lion, when he has seen from the high lookout
455. that a bull, practicing into battles, was standing far* in the fields, (*procul can mean "far [off]" or "from afar".)
456. flies to [him], the image of coming Turnus is not another.
457. When he believed that this man would be close to his sent spear*, (*missae hastae = dative with special adjective "contiguum".)
458. Pallas went* sooner, if chance should help him, having dared, in any way** (*ire = historical infinitive. **"qua" is not the relative pronoun/adjective, but rather the adverb "qua", which means "in any way".)
459. with unequal strength, and he speaks to great heaven* in this way: (*aethera is a Greek accusative. It is masculine, so "magnum" describes it)
460. "Through the hospitality and tables of my father, which you, a stranger, approached,
461. I pray to you, Hercules, let you be present for my huge undertakings*. (*coeptis = dative of purpose.)
462. Let him see that I am seizing bloody arms from
463. him* half-dead, and let the dying eyes of Turnus bear [me] the victor." (*"Sibi" refers back to the subject of "cernat", i.e. Turnus. It literally translates "himself", so if you care more about being literal than sounding good, you can translate it that way. It is dative of separation.)
464. Hercules heard the young man, and he presses
465. a great groan beneath the bottom of his heart and he pours out empty tears.
466. Then the father addresses his son with friendly words: