(i) Birds fly. (action of doing)
(ii) Alexander was a great warrior (action of being)
(iii) Uttej has a foreign car. (action of possessing)
Regular Doing Verbs (RDV) are - do / does / did, take, see, write etc.
The forms of 'be' are - am / is, was, are, were etc.
Possessive forms are - have / has / had.
Verbs change their form according to the tense i.e., into Present Simple, Simple Past and Past Participle.
Eg: Take - took - taken and the like.
In addition to these verbs, Helping Verbs or Modals are there.
They are - may / might, will / would, can / could, shall / should etc.
Eg: (i) It may rain any moment.
(ii) Anil can swim well.
(iii) Nikitha won't come to school today.
(won't = will not)
Note that the modals (may, can, won't) are used with regular doing words (Verbs) (rain, swim, come respectively).
An adverb is a word which describes or adds something to the meaning of a verb, an adjective or another adverb. Eg: Rakshith plays cricket well.
Most of the adverbs are formed by adding -ly to the adjectives.
Eg: Beautiful (adj) - beautifully (adv)
Excellent (adj) - excellently (adv) etc.
But, good (adj) - well (adv)/ fast (adj) - fast (adv) etc.
The following are the main kinds of adverbs:
Time - Soon, Late, Already, Now, Then, Daily etc.
Place - In, Inside, Here, There, Outside, Below etc.
Degree - Much, More, Almost, Enough, Very, Too etc.
Manner - Well, Badly, Fast, Slowly, Quickly etc.
Number - Once, Twice, Always, Often, Some times, Never etc.
Eg: The underlined words are adverbs.
(i) Come and sit here
(ii) The horse is a fast animal. It runs fast. (fast - adj; fast - adv)
(iii) The patient is almost dead.
(iv) 'You are late again'
(v) I go to movies once in a week.