Pronunciation of -ed in Adjectives

Many English adjectives have the ending -ed. They are formed from verbs as in cooked, processed and typed. However, a few adjectives have a different pronunciation in which the -ed ending is a separate syllable. 

These adjectives are relatively few. Here are five common ones:

aged
beloved
blessed
cursed
learned

When these words are used as verbs, the -ed ending is pronounced [d] or [t]. The pronunciation [Id] only applies when they are used as adjectives, and in most cases, as attributive adjectives. Here are examples where the [Id] pronunciation is used:

The aged leader announced his resignation.
My beloved grandparents are visiting tomorrow.
The baptism was a blessed moment.
They left the cursed home.
This is a learned journal.

In the case of They left the cursed home, cursed can also be pronounced with the ending [t]. Many speakers consider the pronunciation [Id] a bit archaic.

The adjective learned is pronounced with the pronunciation [d] in certain cases such as learned behaviour.

If the adjective aged has the meaning of age, the ending is pronounced [d]. For example, All high school-aged students will take part in the field trip uses the ending [d].

The ending [d] or [t] is used when these words function as verbs. Here are examples:

This cheese has been aged for 10 years.
They are dearly beloved by everyone.
Everyone felt blessed. (The spelling blest can also be used here).
The enemies cursed one another.
We have learned so much in the past year.

English adjectives formed from verbs which have the ending -ed are usually pronounced with a word-final [d] or [t]. However, certain adjectives are pronounced with the ending [Id] when they are used as attributive adjectives. The adjective learned is an exception and retains the pronounciation [Id] in predicates as in She is very learned. The pronunciation [Id] reflects an earlier pronunciation of the English language.