The professor assumed that Michelle probably have stayed up late last

[quote="gregfromnancy"]from the gmatclub ultimate grammar book
test 2

41. The professor assumed that Michelle probably have stayed up late last night since she fell asleep in class.
a) Michelle probably have stayed up
b) for a fact Michelle was staying up too
c) Michelle must have stayed up
d) Michelle probably must had stayed up
e) it was possible of Michelle staying up

A
have done is not used for past action. there are many uses of have done. look at the grammar books for this point. A is wrong
B, "fact that +clause" . this is grammatical basic error
D , there is no "must had done" in english
E, there is no this pattern in English.

The professor assumed that Michelle probably have stayed up late last night since she fell asleep in class.
a) Michelle probably have stayed up
b) for a fact Michelle was staying up too
c) Michelle must have stayed up
d) Michelle probably must had stayed up
e) it was possible of Michelle staying up

This question is from Gmat Club Grammar Book. Practice Test 2 (41). The OA is C. My confusion is should not it be the had stayed up instead of have stayed up?

The professor assumed that Michelle probably have stayed up late last night since she fell asleep in class.
a) Michelle probably have stayed up
b) for a fact Michelle was staying up too
c) Michelle must have stayed up
d) Michelle probably must had stayed up
e) it was possible of Michelle staying up

This question is from Gmat Club Grammar Book. Practice Test 2 (41). The OA is C. My confusion is should not it be the had stayed up instead of have stayed up?

The Past Perfect expresses the idea that something occurred before another action in the past. It can also show that something happened before a specific time in the past.

For detail visit the following Link - https://www.englishpage.com/verbpage/pastperfect.html

Whereas -

Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT use the Present Perfect with specific time expressions.

For detail visit the following Link - https://www.englishpage.com/verbpage/presentperfect.html

Thus, Have stayed up is good here...

Sorry, I am still not very much clear on this. Both professor assumed and she fell asleep in class are in past. Michelle must have stayed up last night describes an action which occurred before the past actions professor assumed and she fell asleep in class. So, should not it be past perfect instead of present perfect?

Regards.

This question focuses on the probability of something happened.

"must had done sth" is wrong gramatically. Hence D is out.

Between A and C, the probability in C is higher. Also, the professor has a strong evidence that "Michelle fell asleep in class", so the correct choice is C. In A, professor made a guess but not sure about it.

C is the most appropriate answer here. However Michelle " probably had stayed up" would have been more appropriate as the sentence talks of 2 events and one is before the other . The use of past perfect tense makes more sense than present perfect tense. I.e Michelle fell asleep (later event) after she had stayed up (earlier event) .
Only answer option D uses past perfect tense. However D is wrong as "probably must had"is redundant. Probably indicates a probability of an event happening while "must" indicates that that event is certain. Usage of both probably and must for the same event is redundant. Also must cannot precede had as it is idiomatically incorrect.
So the next best answer here is C. Another pointer here is since the time frame is not mentioned, present perfect seems a safe option.

Usage of Present Perfect Tense or Past Perfect tense. Two events are specified in the question where one is before the other and hence Past Perfect tense seems appropriate. However there is no answer option with the past perfect tense (without errors) . Also the time frame is not mentioned in the question which makes the use of present perfect tense also appropriate. Kindly advise !!

I agree with you that past perfect would be more appropriate here. However, the only option is D, which is redundant (probably must had...) Between A and C, I choose C, as it is more precise.

Remember: We are searching for the most appropriate answer (although it might sometimes seem awkward as well)!

Both your posts are very clear and logical. I agree with your points.

- must had stayed up-' had' is an incorrect verb after the modal "must'. "must have stayed up" is ok. Or you may drop -must- from choice D and it will be ok

D. The professor assumed that Michelle probably had stayed up late last night since she fell asleep in class.

Thanks for the clarification.

You are welcome !!

Hi sayantanc2k,

I rejected the choice C as it changes the meaning of the original sentence. Original choice shows the possibility while choice C shows the certainty. To me, no choice seemed to be correct. so, I end up selecting A; however, I knew that there should be past perfect instead of present perfect in choice A.

Please advise how to select one choice between two when both seems to be incorrect.

I rejected the choice C as it changes the meaning of the original sentence. Original choice shows the possibility while choice C shows the certainty. To me, no choice seemed to be correct. so, I end up selecting A; however, I knew that there should be past perfect instead of present perfect in choice A.

Please advise how to select one choice between two when both seems to be incorrect.

A is wrong in this case. The sentence "Michelle probably have stayed up" is idiomatically wrong. Meaning wise the subject of the sentence after the word "that" would be Michelle (singular) while the verb (have) is plural. There would be a subject verb disagreement in option A.

Option C is correct as we can use "have" after the modal verb "must". Try thinking of an example to clear this concept ." He must have slept off"is correct while "He probably have slept off" is wrong.
If "probably" is to be used in the sentence we can use "He probably has slept off."

Hope this clears your doubt .

the only difference btw option a and c is probably (which is a possibility ) and must (certainty) . when in assumption do we use probably or must after" that " ? IMO A as it is an assumption.