El elogio de la dificultad

ARM
to cost someone an arm and a leg = cost somebody a lot of money.
That car cost him an arm and a leg.
to fold somebody in one's arms = hold somebody closely by putting one's arms around him.to give one's right arm = be prepared to make a great sacrifice in order to do something.
He would give his right arm to have a new house.
to hold/keep someone at arm's length = keep someone at adistance.
I can't stand her, that's why I keep her at arm's length.
to twist somebody's arm = persuade somebody to do something he doesn't want to do.
Nobody twisted my arm about coming here.
towelcome/accept/receive something with open arms = with enthusiasm.
to walk arm in arm = with the arms bent around each other's.
as long as your arm = very long.
 
HAND
to be hand in glovewith someone = be in close relationship with someone.
He was found to be hand in glove with the enemy.
to be an old hand at something = be very experienced at something.
to eat out of someone'shands = be under someone's influence.
She soon had the class eating out of her hand.
to give/lend someone a hand = help someone.
to have/take a hand in something = be partly responsible forsomething.
The party was great, I bet he had a hand in it.
to have one's hands full = be extremely busy.
to know something like the back of one's hand = be thouroughly familiar with something.
He's ataxi driver, so he knows the city like the back of his hand.
to live from hand to mouth = satisfy one one's present basic needs.
He won't start saving money when he's been living from hand to mouthall his life!
to show one's hand = let others know one's intentions.
I suspect they're planning something but they haven't shown their hand yet.
to wait on someone hand and foot = serve somebody byattending to all his needs.
He seemed to expect to be waited on hand and foot.
 
DOG
a dog's life = constantly worried, troubled or miserable
every dog has his day = everyone can succeed...