Marks or phrases in the perfect tense include: 1 Have/has + past tense: an action or state that began at a certain time in the past and continues until now. For example: - I have been to Paris - He has a PhD in economics 2 Have/has + past tense + perfect tense: an action or state that has been completed before a certain time in the past. For example: - She has lived in New York for years - We have finished the work on the project 3 Have/has + infinitive: an action or state that has not happened before a certain time in the past. For example: - I will have been studying English for a year by the time I graduate - He would have been a famous painter if he had not been born in a humble family. 4 Will/would + have/has + past tense: an action or state that has been completed before a certain time in the future. For example: - She will have graduated from college by the time she enters the workplace - He would have been a success he had not lost his job.