* note that it is the sound that is important, not the letter or spelling. For example, "fax" ends in the letter "x" but the sound /s/; "like" ends in the letter "e" but the sound /k/.
Exceptions
The following -ed words used as adjectives are pronounced with /Id/:
aged
blessed
crooked
dogged
learned
naked
ragged
wicked
wretched
So we say:
an aged man /Id/
a blessed nuisance /Id/
a dogged persistence /Id/
a learned professor - the professor, who was truly learned /Id/
a wretched beggar - the beggar was wretched /Id/
But when used as real verbs (past simple and past participle), the normal rules apply and we say: