Here's why:
* Short vowels are typically represented by the letter followed by a consonant. For example, "cat" has a short "a" sound.
* Long vowels can be represented in various ways, including by a vowel followed by a consonant and a silent "e" at the end of the word (as in "mimic").
The "i" in "mimic" is followed by a consonant ("m") and a silent "e". This creates a long "i" sound, similar to the "i" in "bike" or "time."