容易

It's easier said than done.

He is easy to approach. / He is accessible.

learn the letters without much effort

as easy as shelling peas

easy prey

easy-to-reach place

easy victim

The stuff melts easily.

get seasick easily; be liable to seasickness

be subject to headaches

be apt to fidget

easy to get mixed up

be apt to catch cold; be susceptible to cold

be apt to meet with accidents; be accident-prone

deteriorate easily