If the verb ends in a short vowel and a consonant (stop) (except "y" or "w")
To form the simple past with irregular verbs
With verbs that end in a consonant and a "y" (try)
To form the simple past with regular verbs
For regular verbs that end in an "e" (believe),
the "y" is changed to an "i" (tried)
we double the final consonant (stopped)
there is no established norm for forming them
we only add "-d" (believed)
we use the infinitive and add the ending "-ed"