DOI link for Simple past
Simple past book
The past-tense form of regular verbs is very simple. However, the particles that introduce questions, negation, etc., differ somewhat in the past tense from other tenses.
The past tense of regular verbs in both conjugations consists simply of the imperative singular stem, plus lenition of the initial consonant. If the consonant is one that cannot be lenited, then the past tense and imperative forms are identical, except that the past tense in a sentence will be followed by a subject pronoun or noun.