were delivered or have been delivered? which is correct?

Both are used in a very similar way to indicate an action in the past and are sometimes, but not always, interchangeable. Both are in the Passive voice (the verb is 'to deliver' and the passive form is 'to be delivered'). The Passive voice uses the verb 'to be' as the auxiliary where the object in an active form ("UPS delivered the packages") becomes the subject in the passive ("The packages were delivered by UPS"). The passive form has the structure: Subject + finite form of 'to be' + Past Participle We therefore need to ask what the difference is between '[they] were' and '[they] have been' 'were' is the plural forn of the Simple Past tense. It usually indicates an action which took some time to complete or was happening over, during or at a particular time in the past. ("The packages were delivered on Friday"; "The packages were delivered at 7:08am precisely"). It is also often used when a thing either did or did not happen (Q: "Were the packages delivered?" A: "Yes, they were delivered"). 'have been' is the plural form of the Past Perfect tense. It generally means that the action happened and finished at some point in the past. ("The packages have been delivered" is correct; "... have been delivered on Friday" is incorrect). As you can see, there are times when it is not important whether the action took some time to complete or happened at a particular time. What is important is whether it happened or not, so sometimes both forms may be used interchangeably: "Have the packages been delivered?" may be answered with either "Yes, they have been delivered" (simple confirmation) or "Yes, they were delivered on Friday" (confirmation giving extra information not specifically asked for) I'm afraid that English tenses and the ways they are used are always a big difficulty for people whose mother tongue uses other ways to express past, present and future actions. Here is a table which, I think, explains usages (in the Active voice) quite well: http://www.ego4u.com/en/cram-up/grammar/tenses Unfortunately, I can't find a similar one for the Passive voice usage!

Examples: The package was delivered. The packages were delivered on August 12th. The packages were shipped and they have been delivered. I hope I answered your question.