Search results
Results from the WOW.Com Content Network
In modern English, the auxiliary verb used to form the present perfect is always to have. A typical present perfect clause thus consists of the subject, the auxiliary have/has, and the past participle (third form) of main verb. Examples: I have done so much in my life. You have gone to school. He has already arrived in America.
The perfect passive is usually made with the perfect participle combined with sum, e.g. missus sum 'I was sent, I have been sent', ductus sum 'I was led, I have been led'. Some perfect tenses have an irregular stem, for example sum, fuī 'I am', eō, īvī 'I go', ferō, tulī 'I bring, I bear', tollō, sustulī 'I raise, I remove'.
The choice of present perfect or past tense depends on the frame of reference (period or point in time) in which the event is conceived as occurring. If the frame of reference extends to the present time, the present perfect is used. For example: I have written a letter this morning. (if it is still the morning) He has produced ten plays.
There are seven main infinitives. They are in the present active, present passive, perfect active, perfect passive, future active, future passive, and potential active. Further infinitives can be made using the gerundive. The present active infinitive is the second principal part (in regular verbs).
The perfect aspect (or perfect progressive) can also be combined with marking for the passive voice. Perfect passive forms can be constructed by replacing the participle of the main verb with the corresponding participle of be followed by the past participle of the main verb: it has been eaten; it will have been eaten; it has been being eaten.
There is a perfect infinitive (to) have written and a perfect progressive infinitive (to) have been writing, and corresponding present participle/gerund forms having written and having been writing. A perfect subjunctive (have written) is also sometimes used. Future and conditional perfect forms are given below.
The present tense used in the condition clause may take the form of the simple present as in the above examples, or the present progressive, present perfect or present perfect progressive as appropriate (according to general principles for uses of English verb forms): If he is sleeping when we arrive, we shan't wake him. (present progressive)
Another way of expressing a passive verb in the apodosis of an unreal conditional in indirect speech is to use the perfect infinitive of possum combined with a present passive infinitive; that is, to write 'could have been done' instead of 'would have been done', since the two are close in meaning: [183]