magic e
Generally speaking, we prefer not to teach rules — so much cognitive load, and so many exceptions in common words (have, love, give). These have their own rule to explain the exception (words don’t end in the /v/ sound, so add a silent e).
But for those who would like a rule to explain a common english anomaly:
“An ‘e’ close behind another vowel (with no more than one letter in between) usually makes the first vowel say its name, and the ‘e’ is usually silent. Like in ‘bite’, the ‘e’ is silent and the ‘i’ says its name. Without the ‘e’, it would be ‘bit’, and the ‘i’ would be the short sound.
bit → bite
cut → cute
hop → hope
tap → tape
The magic e at the end turns a short vowel into a long vowel — it makes the vowel say its name.