Activity Confusion in have has ad had

please give me suggestion when we need to use have had and has

’Had’ is the past tense of both ‘has’ and ‘have’.

  • have. Have is used with some pronouns and plural nouns: …
  • has. Has is used with the third person singular. …
  • contractions. I have = I’ve. …
  • negative contractions. …
  • ‘have’ and ‘has’ in questions. …
  • ‘have got’ and ‘have’ …
  • ‘have’ and ‘has’ verb tenses. …
  • modal verbs: ‘have to’

have had is used in sentence whenever you want to use the present perfect tense.

For eg.
I am sick, I have had a headache all day.