Excluding four common irregular verbs, the principal parts of all other English verbs are the infinitive, preterite and past participle. All forms of these English verbs can be derived from the three principal parts. Four verbs have an unpredictable 3rd person singular form and the verb to be is so irregular it has seven separate forms. Lists or recitations of principal parts in English often omit the third principal part's auxiliary verb, rendering it identical to its grammatically distinct participial form. For example, the verb "to take" has the principal parts "take–took–(have) taken". The verb "to bet" has "bet–bet–(have) bet" and the verb "to break" has "break–broke–(have) broken". With irregular verbs the simple present 3S (he, she, it) is derived from infinitive+'s' with the exception of spelling changes such as: catch-catches, fly-flies and teach-teaches, which follow the same rules for regular 3S verbs.