助一臂之力

to lend a helping hand (idiom)

to help / to assist

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

arm

(possessive particle, literary equivalent of 的[de5]) / him / her / it

power / force / strength / ability / strenuously