It is 'cost'. For example, if the noun used is first or third person plural, it is always 'have cost'; if the noun used is third person singular it is 'has cost'.
Present perfect is have/has cost
They/We/You/I have cost us a fortune.
He/She/It has cost the school lot of money
The present perfect tense of "cost" is "has/have cost." For example, "The new laptop has cost me a lot of money."
The present perfect tense of "hid" is "have/has hidden."
The present perfect tense of "exist" is "has/have existed."
The present perfect tense of "was" is "have been".
The present perfect tense of "clap" is "have clapped" or "has clapped."
"have tried" is the present perfect tense.
Present perfect tense.
The present perfect tense of "hid" is "have/has hidden."
present tense past tense future tense present perfect tense past perfect tense future perfect tense present progressive tense past progressive tense future progressive tense present perfect progressive tense past perfect progressive tense future perfect progressive tense
The present perfect tense of "are" is "have been."
The present perfect tense of leave is have/has left. The present perfect tense of eat is have/has eaten.
"have tried" is the present perfect tense.
The present perfect tense of "exist" is "has/have existed."
The 6 forms of perfect tenses are: present perfect, past perfect, future perfect, present perfect continuous, past perfect continuous, and future perfect continuous.
The future present perfect tense of "talk" is "will have talked." For example: "By next week, I will have talked to my boss about the project."
Present Tense, Paste Tense, Future Tense, Future Perfect Tense, Present Perfect Tense, Past Perfect Tense
The six main tenses of verbs are: present, past, future, present perfect, past perfect, and future perfect. Each of these tenses indicates a different time frame in which an action takes place.
The present perfect tense of hurry is "have/had hurried."