Most verbs add a simple –ed (if the last letter is a consonant) or –d (if the last letter is a vowel) to the infinitive to form the simple past tense. These are called Regular Verbs.
Work => Worked
Like => Liked
If the verb ends in the letter Y, change the Y to I and then add –ed.
Copy => Copied
If the verb ends in a consonant preceded by a short vowel sound, you have to double the consonant at the end prior to adding –ed.
Plan => Planned (not planed)
Mop => Mopped (not moped)
In my blog where I store my Tips of the Day for posterity, one of the most popular hits is the Planed vs. Planned entry I did a year ago. I get a couple of people looking for guidance on that every day.
In addition to these rules of thumb for regular verbs, there is a whole slew of irregular verbs that do not follow these rules. Some have the same present and past tenses, but a different past participle. Some are the same for all three forms. Some are different for all three forms. I’m going to cover
the latter today.
drink drank drunk
ring rang rung
sing sang sung
sink sank sunk
shrink shrank shrunk
swim swam swum
And my very favorite of this series comes from a cartoon movie, How the Grinch Stole Christmas.
There’s a song that describes how mean this character the Grinch is:
“You’re a mean one, Mr. Grinch, ….
You’re a nasty, wasty skunk!
Your heart is full of unwashed socks, your soul is full of gunk,
Mr. Gri –INCH!
The three words that describe you best are as follows, and I quote:
‘Stink, stank, stunk!’”