NB The word ступня "foot" has a much more restricted usage than нога in the sense of "foot." For example, the following expressions may be used with нога, but not with ступня: ноги замёрзли "one's feet got cold," промочить ноги "to get one's feet wet," мозоль на ноге "a blister on one's foot." The word ступня is used mostly in expressions that describe the size or the shape of the foot, and in some expressions that refer to sensations or injuries.