The short vowel sounds are the A in "cat," the E in "pet," the I in "sit," the O in "hot" and the U in "up." Usually, short vowels have simple spellings. Note: "bear" is listed with the pronunciation "bair" on dictionary.com, though some teachers may use the basic rule that "ea" can sound like a short E or a long E.
The short answer is that English spelling is largely arbitrary, and does not represent English pronunciation; there are always exceptions, like this, to any spelling rule. The important thing is not to expect English spelling to represent pronunciation; because it doesn't. No matter what they told you in school.
is that beer is (uncountable) an alcoholic drink fermented from starch material commonly barley malt, often with hops or some other substance to impart a bitter flavor or beer can be one who is or exists while bear is a large omnivorous mammal, related to the dog and raccoon, having shaggy hair, a very small tail, and