in conversation, how different are these "would, could, should"?

Question

Of course, I know 'would, could, should' is past of "will, can, shall'

but in conversation, I really dont know how to use ^^

for instance,
->I would need to get a new TV --->' would' means that 'to do strongly something'

PS: My Question is correct in grammar ?

Answer 1

should

Should is used to give advice and make recommendations and to talk about obligation, duty and what is expected to happen. Reference is to the present and the future. Should is similar to must but is not as strong as must:

You should always wear a helmet when you go out cycling on busy roads.


Once the pack is opened, the cooked meat inside should be consumed within three days.


Should I tell her that her son is playing truant and skipping school? ~ I think you should. She should know about it.



should and should have

Should combines with the perfect infinitive to form should have + past participle when we want to talk about past events that did not happen, but should have happened. We are talking about an expectation and referring back to past time. Compare the following:

Before Tom leaves for work, his wife advises him:

You should take your umbrella. It might rain. ~ No, I'll be all right. I shan't need it.

But it did rain. When he arrives back home, his wife says:


What did I tell you? You should have taken your umbrella. Then you wouldn't have got wet.

Reference to the present and future:


You should try and smoke less, Henry. Your health isn't very good and it's getting worse.

Reference to the past:


I should have given up smoking years ago, Mary. If I had, I wouldn't be in such bad shape now.



would

If we want to talk about an unreal or unlikely situation that might arise now or in the future, we use a past tense in the if-clause and would + infinitive in the main clause. Compare the following and note that would is often abbreviated to 'd:

How would you manage, if I wasn't here to help you? ~ I'd manage somehow. I wouldn't bother to cook. I'd go out to eat or bring home a take-away. I'd ask your mother to help me with the washing and the ironing. I know she'd help me.
would have

If we want to refer to the past and make a statement about things that did not happen, we need to use had + past participle in the if clause and would have constructions in the main clause. Note in these sentences that we can use 'd as the abbreviation for both had in the if-clause and would in the main clause:

If he'd taken an umbrella, he wouldn't have got wet on the way home.


If he'd taken his umbrella, he'd have stayed dry.


could

Could can be used to ask for permission, to make a request and express ability in the past. Compare the following:

Could I borrow your black dress for the formal dinner tomorrow? ~ Of course you can!


Could you do me a favour and pick Pete up from the station? ~ Of course I will!


I could already swim by the time I was three. ~ Could you really? I couldn't swim until I was eight.
could have

As with would have, and should have, could have is used to talk about the past and refers to things that people could have done in the past, but didn't attempt to do or succeed in doing:

I could have gone to university, if I'd passed my exams.


If he'd trained harder, I'm sure he could have completed the swim.


Note the difference between would have and could have in the following two examples. Would have indicates certainty that he would have won if he had tried harder, could have indicates that it is a possibility. Might have is similar in meaning to could have, although the possibility is perhaps not quite as great:
If he'd tried a bit harder, he would have won the race.

If he'd tried a bit harder, he could have won the race.

If he'd tried a bit harder, he might have won the race.



should have / could have / wouldn't have

Note the way in which all three of these modals are combined in these exchanges which refer to a meeting that has just taken place:

Why did you come to the meeting? It didn't need both of us. You should have known that I would be there. ~ How could I have known you'd be there? I haven't spoken to you for a fortnight! ~ If I'd known you were intending to go, I certainly wouldn't have gone!

You will sometimes see would have written as would've, should have as should've and could have as could've.

Answer 2

Firstly would, could and should are not always the past particple of will, can and shall. They can be used in the present tense.

You would say 'I would need to get a new TV' if you were talking about a situation that arises. So "What if your TV broke?" "I would need to get a new TV".

Should means something you're supposed to do or is good. "I should give money to charity, but I can't at the moment."

These are only a few examples of their meanings, they have more than one.

Answer 3

Yes, they are the past forms of the verbs sited but they are modal verbs which means they can be used in a variety of different ways, and in different ways to express different times (past, present and future)

Firsly, to look at your example; "I would need to get a tv." -

This can only be used as part of a conditional sentence, for example: "If my tv stopped working, I would need to get a new tv." In this instance, "would" is used as the past of "will" as a sense of inevitability - it is necessary, but the time is present/future/general. (2nd conditional - hypothetical).

If we continue with the same conditional sentence you can use different endings: "If my tv stopped working, I could get a new tv". Here the meaning is different. "I could get a new tv" (It is possible) or "I could stop watching tv" (it is also possible).or "I could get it repaired" (equally possible) "Could" being the past of "can" as possibility NOT ability. But this is NOT expressing past time - again 2nd conditional for present/future/general time in a hypothetical situation.

Using "could" for ability is also possible: "If I passed the driving test, I could give you a lift", "I could go to England if I had a visa." etc

"Could" is also used as the past of "can" for ability and permission: "I could run fast when I was young." etc (ability) or "My mother told me I could go to the party." (permission). Both of these sentences refer to past time.

"Should" has the idea of being a good idea or something imposed on us that we may or may not comply with. For example: "Passengers should wear seat belts.", "I should stop smoking." (general time). When used to express past time it isn't used alone : "I should have stopped smoking last year but I didn't.". Here we still have the idea of it being a good idea but the time is in the past, expressed by SHOULD + HAVE + PAST PARTICIPLE.

"Would" and "Could" can also be used to make requests: "Would you mind opening the window?" ,"Could I open the window?" and "should" can be used for advice: "You should go to the doctor.", "Should I change my job?" (again we have the idea of it being a good idea).

"Would" can also be used to refer to habits in the past: "My father would always watch the news when he came home from work." = "My father used to watch the news......."

The more I write, the more (different) examples I can think of!

You should read a good grammar book
You could read a good grammar book
If I were you, I would read a good grammar book
"English Grammar in Use." - Raymond Murphy (CUP),
"Practical English Usage" - Michael Swan (OUP) are both good.

Modals are probably the most difficult aspect of learning English, I think you know more than you think you do because you asked the question. Good luck with improving your (already very good) English.

Answer 4

I ''will'' need to get a new TV.
''to do strongly something'' is wrong = to do something strongly.

These 3 words are used in different context depending on the sentence that uses it.

Answer 5

As you say it is the past tense so and is (usually) conditional so:

I would have needed to buy a new TV but my parents bought me one.

I could have run the marathon but I didn't have time to train.

I should have told you that I loved you but now you are gone.

Answer 6

Would you make love,
could you make love
Or should go down stairs and make me a nice cup of tea

Answer 7

Would: Suggests a promise.
Could: You are able to do a task.
Should: To obey or not to obey.

Answer 8

would ~ will you do it
could ~ are you able to do it
should~ a gut feeling strongly urges you to do so

Answer 9

wold comes from WILL and could comes from CAN and should comes from MUST> it means that could has kind of "ability" meaning in it,and should has some "obligation" meaning. am I clear?!

Answer 10

they each mean something different