lend (one) a hand
To help one; to give one assistance. If you lend me a hand, I can get this done much faster. Lend your mother a hand in the kitchen, will you?
lend (someone) a hand
COMMON If you lend a hand or lend someone a hand, you help someone to do something. If I'd known, I'd have been glad to lend a hand — you should have called me up. I do the cooking and Bryan lends a hand with the washing-up. Could you lend me a hand with these books, please? Note: A hand is used in many other structures with a similar meaning. I used to give Mary a hand with the catering. Need a hand with those? I could see you'd want a hand with the children.