Past Simple

We use the simple past to refer to an action in the past that is finished.

In the positive form, for regular verbs, add an -ed but when the verb ends in consonant change the -y to -ied.

Example: fly - flied


Use the conjugated helping verb 'did' not (didn't) the base form of the verb to make negatives.

Example: (I,You,He,She,It,We,You,They) didn't go to New York last week.

Use the conjugated helping verb 'did' subject the base form of the verb in question forms.

Example: When Did (I,You,He,She,It,We,You,They) leave yesterday?



Credits:
http://www.englishpage.com/verbpage/simplepast.html
http://www.ego4u.de/de/cram-up/grammar/simple-past
http://www.wikilearning.com/past_simple_pasado_simple-wkccp-3405-8.htm