P's

When the teacher is very strict, the students must mind their P's and Q's.

Source: tatoeba (19074)

When the bartender totals the bill for a customer who is drunk and angry, he must be very careful to mind his P's and Q's.

Source: tatoeba (35611)

Tom had to mind his P's and Q's when he met Mary's parents for the first time.

Source: tatoeba (4219275)

This sentence employs two a's, two c's, two d's, twenty-eight e's, five f's, three g's, eight h's, eleven i's, three l's, two m's, thirteen n's, nine o's, two p's, five r's, twenty-five s's, twenty-three t's, six v's, ten w's, two x's, five y's, and one z.

Source: tatoeba (11146546)