would lend a hand
Si fuera más joven te echaría una mano.
If I were younger, I’d give you a hand.
— El castillo ambulante (2004)
Si estuviera en tu lugar, le echaría una mano.
If I were in your place, I would lend a hand.
Dijo que les echaría una mano.
He said he would lend them a hand.