Regular Irregular Past Participles

How to write them …
Regular verbs have –ed at the endings of the word in their past tense or past participles form while irregular verbs can be the same or changed entirely. * Some examples for regular verbs : * Cook-----Cooked----Cooked * Play-----Played----Played * Gain-----Gained----Gained * Irregular verbs : * Sing----Sang----Sung * Buy---Bought---Bought * Cut----Cut----Cut * Be----Was/Were----Been * Past participle usually comes with has/had/have in front of the participle while simple past may or may not need them.
Simply put, regular verbs always retain their original word even with the addition of inflectional endings (-s,-[e]d, -ing), it’s a rule that must be obeyed. Verbs in anyway deviate from these rules are classified as irregular verbs. The only way for you to know the simple past and past participle forms of these verbs is to read and memorize.

When to use them …
When do we use simple past and past participles ??
Use simple past tense for something that is in the past, completed and not continuing. Past participls are actions started in the past but have a connection with the present.

Simple Past
I bought a new car yesterday.– (just reporting what I did in the past).
Past Participle
I have/I’ve bought a new car. – (expressing that I have a new bike now).
- The Past Participle is used when the time period has NOT finished - i.e. I have seen 3 movies this week (this week has not finished yet). The Simple Past is used when the time period HAS finished - i.e. I saw 3 movies last week (last week is finished).
Past participles are used to describe a past events with multiple actions more clearly and orderly.
Ie. After I had eaten breakfast, I went to school.

References :

http://www.perfect-english-grammar.com/present-perfect-or-past-simple.html http://www.myenglishteacher.net/pastperfecttense.html http://grammar.about.com/od/rs/g/regverbterm.htm
http://grammar.about.com/od/il/g/irregularvterm.htm

References: : http://www.perfect-english-grammar.com/present-perfect-or-past-simple.html http://www.myenglishteacher.net/pastperfecttense.html http://grammar.about.com/od/rs/g/regverbterm.htm http://grammar.about.com/od/il/g/irregularvterm.htm