perfect tense: question on "unspecified time"
73062
Must present perfect tense be used if the action takes place more than once?
53495
Why is 'present perfect' present if it happened in the past? And why is it 'perfect'?
54114
When should one use the "recent past"? How much time should have passed?
128296
mixed tenses/tenses agreement
153687
What tense should I use to describe something in the past but probably is still true?
40315
When will "Present Perfect vs. Past Tense" cases be affected by culture?
156031
When a sentence includes a word like 'today' that indicates present time, can a past form of verb be used?
36273
Should you say hour or hours in this type of sentence?
23177
Tense change: previous actions on something that's currently true
72584
Answering about the time
93810
How is "I have come" + infinitive different from Present Perfect?
28026
Can we use "Now" (not until now or until then) in past tense sentences
42497
How do you say that some time had elapsed?
70232
Is 'long time no see' grammatically correct?
131253
Why doesn't the auxiliary will qualify as future tense?
64898
Future Simple and Future Perfect
18312
When is using the past perfect tense not necessary?