Examples:
In a restaurant:Waiter, sorry to make a fuss, but this bread is stale.
I think I’d better open the window in the conference room; it’s a bit stale* in there.
Can you remind me of how the company’s accounts system works?
am sorry, my mind is a little stale on this matter.°
Note the word Stalemate which describes the situation where neither side in a dispute or negotiations can progress or win,
e.g.
It’s clear that we’ve reached a stalemate; we’d be better off starting again.
The word Stuffy is probably more common as far as air is concerned.
i.e. I have forgotten how it works.
1) The room smelled musty and stale.2) The bread/biscuits/cake had gone stale.3) The pub smelled of stale beer.4) Her performance has become stale.5) This bread is going stale.6) French bread goes stale very quickly.7) Your breath reeks of stale cigar smoke.8) I gagged on the stench of stale urine.9) These potato chips are stale.10) It’s so stale in here, Mary,(http://sentencedict.com/stale.html) please open the window and air this place out.11) Their daily diet consisted of a lump of stale bread(sentencedict.com), a bowl of rice and stale water.12) The phony glamour of night clubs soon became stale and boring.13) The public bar was thick with stale tobacco smoke.14) He was becoming stale and running out of ideas.15) There was a powerful smell of stale beer.16) Flowing water does not get stale.17) Other marriages might go stale , but not theirs.18) The bread was stale and rock-hard.19) They bait the mousetrap with stale cheese.20) The room smelled of stale sweat and coffee.21) The atmosphere was stale with cigarette smoke.22) The room smelled of stale sweat.23) Her relationship with Mark has become stale.24) She leaned away from his stale beery breath.25) A miasma of stale alcohol hung around him.26) This bread is fresh/stale.27) A foul smell of stale beer permeated the whole building.28) The smell of stale smoke hit him as he entered.29) The air of the room was fetid with stale tobacco smoke.30) In the cathedral vaults the air was dank and stale.