Modal verbs are, without a doubt, a very important topic in English. They are very common, so you need to be able to recognize them and determine the value. Also, many phrases are simply impossible to compose / translate without knowledge of certain modal verbs. Some of them have very close significance, however, they still cannot be replaced by each other. Such verbs include should, ought to and need. How do they differ and in what situations should they be used? First things first.
What is a modal verb
First you need to understand what modal verbs are. First of all, they can indicate the possibility, probability, necessity of any action. In Russian, the words “can,” “should,” “must,” “must,” etc. correspond to these meanings. Moreover, modal verbs are not used independently, but only together with the semantic verb in the infinitive.
In the sentence together, they play the role of a compound verb predicate. Moreover, modal verbs alone are insufficient because they do not have all tenses. Some of them are used only in the present tense, and cannot form the past tense independently.
Also, after the modal verb, the semantic infinitive is placed without the particle to. But ought to refers to the exception to this rule that you need to remember.
Modal verb ought to
Very often, many people first confuse the verbs ought to and should, and do not know which is better to use. Both of them can be translated as follows. However, they still have slightly different shades of meaning. The modal verb ought to express what is called urgent recommendation, advice, or moral duty.
For instance:
- He ought to help his grandfather. “He should help his grandfather.”
- You are so nervous. You ought to be more patient. “You're so nervous.” You should be more patient.
The advice that is expressed using this modal verb implies that the speaker wants everyone to listen to him. The expression will carry a certain significance.
The modal verb should
As mentioned above, the modal verbs should and ought to have a very close meaning. Should also express advice, moral duty, approval or disapproval of something. And sometimes it is possible to use the modal verb ought to instead of should. But still there is some difference. Should - this is just a "should." Not very strict instruction, a little advice. To some extent, should sound softer and less demanding than ought to.
Example:
- You should read this book. “You should read this book.”
That is, the modal verb ought to in English has a greater shade of rigor. Of course, this is not an order, but the advice will sound a little tougher than if it should have been used. And most often ought to be preferred when it comes to moral duty.
Example:
- You ought to help your mother when she become old. “You have to help your mom when she gets old.”
From this proposal it is clear that helping parents is something natural, a moral duty for everyone, and not just a recommendation or friendly advice.
Modal verb need
Unlike the modal verb ought to, need does not express advice, but the need to perform an action, can be translated as “necessary”. Moreover, the verb need should be used carefully. It is used as semantic, but in the meaning of "need." It is very important to distinguish between these two situations and not to confuse them.
An example of using need as a semantic verb:
- I need some sleep. - I need to sleep.
- I need your help. - I need your help.
- I don't need your advice. “I don't need your advice anymore.”
In all these sentences, the speaker wants or does not want to receive something. He needs something.
An example of using need as a modal verb:
- You needn't get up so early today. “You don’t have to get up so early today (no such need).”
- The water is clean. You needn't boil it. - The water is clean. You do not need to boil it (no need).
These examples demonstrate the need for action, not the need for something.
The use of modal verbs should and ought to and the past tense
As already mentioned, modal verbs are insufficient. They cannot independently form various temporary forms. But what if you need to say something that should have been done a long time ago? Or, conversely, what was not worth doing? For example, a couple of days ago. Perfect Infinitive comes to the rescue here.
It is necessary to return to the modal verb ought to. In combination with the indefinite form of the verb (Indefinite Infinitive), it is used in sentences related to the present or future. With Perfect Infinitive, the actions described in the sentence will occur in the past tense.
Example:
- You ought to do it. - You should do it (today or tomorrow) => You ought to have done it yesterday. “You should have done it yesterday.”
The first example refers to the present or future, and the second demonstrates the action that occurred in the past.
- You ought to send the letter. “You must send this letter (today or at some point in the future).” => You ought to have sent the letter yesterday. (You should have sent this letter yesterday).
That is, to convey actions that occurred in the past, have is put before the semantic verb, and the verb itself takes the third form (if it is incorrect), or adds the ending –ed.
With should be the same situation. Examples:
- She was so sad. He shouldn't have said that. “She was so sad.” He should not have said that.
- You should have been more careful yesterday. “You should have been more careful yesterday.”
The modal verb need and past tense
Need as a modal verb is used with Present Indefinite in interrogative and negative sentences. And such speech constructions belong to the present. But sometimes it must be said that there was no need to perform any action. Such an offer will relate to the past tense, and Perfect Infinitive will come to the rescue again. Examples:
- You needn't get up so early. “You don't have to get up so early.” => You needn't have got up so early. - You didn’t have to get up so early (in vain you got up so early).
- You needn't go to university. “You don't have to go to university.” => You needn't have gone to university. - You did not need to go to university (there was no need).
That is, the past tense in combination with the modal verb need says that something was done in vain, and there was no need to do this.