Past simple
The simple past is a verb tense that is used to talk about things that happened or existed before now. Forming the past simple tense of regular verbs is mostly straightforward, and you use the same form for the first, second, and third persons, singular and plural.
Verbs that form the simple past tense by adding -d or -ed are called regular verbs.
Irregular verbs contrast with regular, that is, they don't have -d or -ed ending in the past tense. You must memorize them.
We use did to make a question in the past tense (Did you ride your bike yesterday?)
We use didn't (did not) to make a negative sentence in the past tense (He didn't ride his bike yesterday.)
Verbs ending in -y: the third person present simple and past simple for all persons change the -y to -ies and -ied.
fly - flies, cry - cries; flied, cried
Exception: if there is a vowel before the -y.
play - plays, pray - prays; played, prayed
Add -es and -ed to verbs ending in: -ss, -x, -sh, -ch
he passes, she catches, he fixes, it pushes 
passed, matched, fixed, pushed
Signal words
Simple Past               
last week,
(\(2\) days) ago,
in \(2010   \)                                            
a completed action in the past (no connection to the present)                                  
We saw a good film last week.