Why do you have to add an extra letter before adding -ed for the past tense for certain words? Stop, becomes stopped

Question

Why do you have to add an extra letter before adding -ed for the past tense for certain words? Stop, becomes stopped

In: 6

Answer 1

To my understanding, it’s to make it clear you aren’t using the past tense of a different but similar word. In your case of stopped, stoped could be the past tense of either stop or stope (don’t think that’s a word but play with me here). A better example is hoped or hopped. One consonant between a vowel and ‘e’ makes that vowel long, but put two consonants and that property goes away.