For example, if a chain-smoking teacher cautions a pupil for smoking, that warning is self-contradictory.

I used to smoke. I was quite a heavy smoker.

Despite "No Smoking" signs, the boat operator was brazenly smoking all the time.

Remove the cap from the ink refill bottle, fill the dropper with ink, and drip an appropriate amount onto the marker's core.

Persons under age are prohibited from smoking.

My father neither drinks nor smokes.

My father smokes a pack of cigarettes a day.

My father used to smoke, but now he doesn't.

My father seldom smokes.

My father lectured me for smoking.

My father stopped smoking.

My father smokes.

My father is a heavy smoker.

She knew better than to smoke a cigarette in his presence.

She went outside to get a breath of fresh air.

She sat and smoked.

She stopped to smoke.

She stopped smoking.

She smokes 20 cigarettes a day.

He stopped to smoke.