Did you stay up all night in preparation for your study? How come in this sentence instead of stayed we use stay, the reason I ask is because the sentence begins with a past tense verb (did )? Is it because of the modal rule(do/did) so stay is in

Did you stay up all night in preparation for your study? How come in this sentence instead of stayed we use stay, the reason I ask is because the sentence begins with a past tense verb (did )? Is it because of the modal rule(do/did) so stay is in

I didn't know I have to stay up all night before I go to the stupid sleep clinic! I'm so tired! Since didn't could be used as a modal shouldn't have be in its base form? Even I know this whole sentence is in the past tense. Or

I didn't know I have to stay up all night before I go to the stupid sleep clinic! I'm so tired! Since didn't could be used as a modal shouldn't have be in its base form? Even I know this whole sentence is in the past tense. Or

Hi Pleasehelp, The usage on and explanations on the modals have been discussed many times. Google "modals". I think the basic explanations can be found quite easily. Is could the past tense of can? What other uses can could

It can be put in present perfect and past perfect using "if" like this: If the train have already left , we shall/will take the next train. (formal present perfect subjunctive) If the train had already left , we should/would

Why should we use 'would' ,'could' in the subjunctive mood and in the future tense? would and could , along with several other verbs, are called modal verbs. The modal verbs don't really have tenses, so you can't really use

they may construct some new airport on islands

Modals: She has to work. Put into negative, question and past using have to = She doesnt have to work hard. Does she hav e to work hard? She didnt have to work hard. The last sentence is past which also could be written = She had to work

Tell me if this is correct. Do isn't a modal verb but it can function as one. Therefore the verb after do is in its base form. Plus, did is the past tense of do so if I add -ed to happen, it would be redundant because did is already in the