Simple Past Tense

THE SIMPLE PAST TENSE
The simple past is used to express an action completed in the past at a definite or particular time and also used to express a past habit:
Example:
The simple past tense is also used for an action whose time is not given but which (1) occupied a period of time now terminated, or
(2) occurred in a period of time now terminated. See diagram.
1 |_______________|
2 |----------x-----------|

Examples: (1) In 1982, Sarah Michelle Gellar starred in a Burger King
Commercial (but she does not star there now).
(2) Gabriel Byrne once worked as a Teddy bear eye installer.
The following adverbs used with the simple past, are usually placed either at the beginning or at the end of a sentence.
Yesterday, last week/month, last year/time, ago/years ago
Example: John Savage lived in South Africa many years ago.
To form the affirmative of regular verbs, add ED to the infinitive without to. Verbs ending in e add d only. The same form is used for all persons.
Examples : Greta Scacchi worked as a ranch cowgirl in Australia.
Lisa Kudrow graduated from Vassar College with a degree in
biology.

The simple past affirmative form of each irregular verb must therefore be learnt, but once this is done there is no other difficulty, as irregular verbs (like regular verbs) and the same form is used for all persons. A list of irregular verbs will be found at the end of this grammar part.
Example : Penélope Cruz became a vegetarian after filming All The Pretty Horses.

The negative structure is formed by adding DIDN’T (did not) after the subject followed by the infinitive form without to of the main verb.
Example : Nicolas Cage didn’t play in Life Is Beautiful.

The interrogative form : DID + the subject + infinitive form without to
of the main verb + ?
Example : Did Nicolas Cage play in Life Is Beautiful?

Spelling notes.
When a verb of one syllable has one vowel and ends in a single consonant, this consonant is doubled before ED.
Example : stop = stopped

Verb of two or more syllables whose last syllable contains only one vowel and ends in a single consonant double this consonant if the stress falls on the last syllable.
Example : pre’fer = preferred
but ‘enter = entered (stress not on the last syllable).

Verb with a final « l » after a single vowel is, however, always doubled.
Example : travel = travelled, signal = signalled

Verb ending in « y » following a consonant change the « y » into « i » before adding ed.
Example : carry = carried
But obey = obeyed (« y » following a vowel does not change).


References:
Grammar Notes from Micheline Perreault
Teen Movieline Magasine, April 2000.
Thomson A.J. and Martinet A.V. A Practical English Grammar, 3rd edition, Oxford University Press, pp147-149.