Desist is a verb, its forms are:
base verb -- desist
third person singular -- desists
past -- desisted
past participle -- desisted
present participle -- desisting
The present forms of the verb "to have" are: I have You have He/she/it has We have They have
A similarly-spelled verb is decease (to die), used almost exclusively as the adjective deceased (dead).Another possible word is desist (to avoid doing), used in the legal phrase "cease and desist" (stop doing and do not do again).
Category is not a verb. Categorize is a verb its forms are: categorize categorizes categorized categorizing
Have is not a "to be" verb. Present tense forms of be: am/is/are Past tense forms of be: was/were Being is the present participle, and been is the past participle.
The noun forms of the verb to infect are infector, infection, and the gerund, infecting.The adjective forms of the verb to infect are infectedand infecting.
a verb
a verb
They are all singular verb forms.
The past participle forms of the verb "be" are "been" and "being".
Verb conjugation
There are three progressive verb forms in English: present progressive (am/is/are + verb-ing), past progressive (was/were + verb-ing), and future progressive (will be + verb-ing).
The verb 'was' is a helping verb. It belongs with other forms of the verb 'be'.