足を棒にする

あしをぼうにする

to walk one's legs off; to walk until one's legs feel like lead; to walk to the point of exhaustion

足が棒になる

あしがぼうになる

to have one's legs become stiff, tired

足を地に付けて

あしをちにつけて

with steady steps, with one's feet planted on the ground

足音を殺して

あしおとをころして

with hushed footsteps

を元にして

をもとにして

based on, built on, made from

足早に

あしばやに

at a quick pace

足しになる

たしになる

to be of help, to be useful

足しにする

たしにする

to make up (an insufficiency), to ease (a lack)

足音を立てる

あしおとをたてる

to walk noisily; to walk loudly

棒を引く

ぼうをひく

to draw a line

鬼に金棒

おににかなぼう

making a strong person even stronger (like giving a metal rod to an ogre), as strong as can be

棒に振る

ぼうにふる

to make a mess of, to sacrifice, to waste

をして

indicates patient of a causative expression

にして

にして

only, just because

足し

たし

top up (e.g. a little bit to remedy an insufficiency)

足し算をする

たしざんをする

add

足音を忍ばせて

あしおとをしのばせて

with stealthy steps; with noiseless footsteps; on tiptoe; stealthily

用を足す

ようをたす

to take care of some business, to go on an errand

足を崩す

あしをくずす

to sit cross-legged, to sit at ease