This chapter clarifies the meaning of "first form," "second form," and "third form" verbs, confirms that using "says" and "crippled" together is grammatically correct, and explains that there's no fixed rule for combining verb forms—it depends on the intended meaning and tense.
First form refers to the infinitive (simple present tense), second form to past tense, and third form to past participle.
There's no strict rule for combining verb forms; it depends on the intended meaning.
Different combinations of verb forms create grammatically correct sentences with different meanings.