Answer:
Many dictionaries mark a short vowel sound by using the vowel with no other markings.
Step-by-step explanation:
A word which does not allow the vowel in it to create that vowel's long vowel sound is called a short vowel.
To understand this better, we can take an example of the word 'cat'. Cat is a short vowel word because there is no long 'A' sound in it. A short vowel word does not have to a three letter word but it is the easiest example to understand since a short word does not allow the long vowel sound to dominate.