How do you determine long or short vowel sounds?

Answer 1

"Long" and "short" are terms borrowed from Classical languages like Latin and Greek. They do not really apply to English vowel sounds, but we use them anyway to describe the difference between monophthongs and diphthongs. In spelling, "long" vowels are sometimes indicated by putting a silent e after a following consonant: hat beside hate. But in the word hatred there is no way of telling from the word's form that its a is "long."

Spelling can be misleading. Sometimes a following silent e does not necessarily indicate a "long" vowel, as in the verb to live. Then again, a word like "short-lived," is usually mispronounced with a "short" i as shortlivved when the correct pronunciation makes it rhyme with arrived. Finally, only usage is a reliable guide.

In English, a vowel sound is truly long or short - that is taking more or less time to say - depending on whether it is followed by a voiced or an unvoiced consonant. Thus the a in hat is short, but the a in had is long.

Answer 2

Long vowel sounds are typically pronounced with the vowel saying its name (for example, "a" in "cake"), while short vowel sounds are usually pronounced with a shorter, more closed sound (for example, "a" in "cat"). The length of the vowel sound is determined by the vowel's position in the word and the surrounding letters.