前部先鋒 You Shall Be My Vanguard
這一去，拿不得唐僧便罷；若是拿了唐僧，決不輕你，就封你做個前部先鋒。」这一去，拿不得唐僧便罢；若是拿了唐僧，决不轻你，就封你做个前部先锋。」
逐句解 Line by line
If this attempt fails to take the Tang Monk, then let it be;
拿不得 puts the verb first — the can-or-cannot shape, so 得 is de. Standing the other way round, in front of a verb, it would mean may not and the character would keep its full tone. The clause ends on a semicolon and what follows is not its match: this half is one condition in ten characters and the next runs to nineteen and climbs.
but if you do take the Tang Monk, I will certainly not treat you lightly. I shall appoint you vanguard of the front division."
前部先鋒 is a real rank from the military romances — the officer who goes ahead of the army. The fiend is running a court out of a cave, with ranks to bestow, and the imp who devised the plan has just been promoted for devising it.
The reward is offered before the plan is executed, which is how this commander does business. He promised nothing to the imp who frightened him and a rank to the imp who cheered him up.
The two halves are built to look like a matched pair and are not, exactly as Pilgrim's were on the crag and again behind the master. Three times now this chapter has set a lopsided if-and-if in front of the reader, and every time the long half is the one that matters.