The task asks to find four irregular Past Simple forms in the provided text, which is about the Past Simple tense and irregular verbs.
Note: The verb 'have' in 'Irregular verbs have irregular forms' is in the present tense. If the task strictly means *past tense* forms, then 'have' would not count. However, given the context of listing irregular verb forms, it's often included as a base form for irregular verbs. If only past tense forms are considered, then the four irregular past simple forms are: left, did, ate, was/were (though 'was/were' is not present in this specific text, it's a common irregular form). Based on the provided text, the most direct irregular past simple forms are left and ate. The word did is the past simple of 'do', used as an auxiliary verb here. The word have is the base form, not the past simple form in this sentence.
If we strictly interpret 'irregular Past Simple forms' as the past tense of irregular verbs appearing in the text, the most prominent ones are:
The word did is the past simple of 'do', which is an irregular verb, and is used here as an auxiliary verb. If auxiliary verbs count, then 'did' is also an irregular past simple form.
The instruction mentions finding forms 'in the email', but no email is provided. Therefore, we are identifying them from the provided text block. The text explicitly states 'Irregular verbs have irregular forms' and gives examples.