This document discusses the past simple tense in English grammar. It explains that to form the past simple of regular verbs, the ending "-ed" is added to the base verb form. For example, "play" becomes "played". It also notes that for the first person singular present simple ("I play"), "do" is understood but not stated, so "I played" uses "did" instead of "do" in the past tense.

1. Past Simple
Primary Verb Present simple
‘ to play’ becomes ‘do play’ ‘Played’ is
Do
‘do’ being understood. ‘did play’
Functions as the key to unlock ‘I play’ means
the infinitive to make it a finite
‘I do play’ ‘I played’ means
verb in case no modal is used
’He plays’ means ‘I did play’
in an assertive-affirmative sentence
in present and past simple tenses ‘He does play’