Some past participles are irregular. For example ... The first part of the perfect tense is the present tense of the verb haber, which is known as an auxiliary verb. An auxiliary verb, also ...

A regular verb is one that conforms to the rules of grammar, whereas an irregular verb is one that does not ... but the most common one you will use besides the present tense will be the past tense.

As you go around telling people what you’ve done, remember to keep the following rule in mind: Nothing gets between haber and the past ... about irregular verbs in the perfect tense in Spanish ...