Le Passe Simple is a past tense in written form of French. It has the same definition as the Passe Compose in that it indicates an action, in the past, which has ended. it does not require a helping verb as in the PC.

To form Er-ending verbs, you must drop the ending and replace with: -ai, -as, -a, -ames, -ates, -erent (1st, 2nd, 3rd singular and plural respectively);

IR and RE-ending verbs are formed by dropping the endings and replacing with: – is, -is. -it, -imes, -ites, -irent  (1st, 2nd, 3rd singular and plural respectively)

These endings apply to all regular verbs.  The difficulty with the Passe Simple lies in all the irregular verbs and many exceptions to the above.