Hi to all my students at the EOI,
Here you can find some theory about the -ed endings pronunciation. Please, read it and ask me doubts about it in class. See u on Monday.
How to Pronounce -ed in English
The past simple tense and past participle of all regular verbs end in -ed. For example:
base verb
(v1) past simple
(v2) past participle
(v3)
work worked worked
In addition, many adjectives are made from the past participle and so end in -ed. For example:
• I like painted furniture.
The question is: How do we pronounce the -ed?
The answer is: In 3 ways - / Id/ or / t/ or / d/
If the base verb ends in one of these sounds: example base verb*: example
with -ed: pronounce
the -ed: extra syllable?
unvoiced /t/ want wanted
/ Id/
yes
voiced /d/ end ended  
unvoiced /p/ hope hoped
/ t/
no
 /f/ laugh laughed  
 /s/ fax faxed  
 /S/ wash washed  
 /tS/ watch watched  
 /k/ like liked  
voiced all other sounds,
for example... play played
/ d/
  allow allowed  
  beg begged  
* 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
