Ought to is a semi-modal verb because it can function as a modal verb and can also act as a main verb. Unlike the modal verbs, it is followed by preposition to, making the main verb that follows it an infinitive, but like the modal verbs, it does not change form for person such as taking an –s for the third person singular. Ought to can be replaced by should as they both have about the same meaning. Ought to can be used in the negative and contracted forms as ought not to or oughtn’t to.
Ought to comes after the subject and before the main verb in a sentence.
Ought to is not used with another modal verb.
- They ought to tell the truth about what happened.
Not: They must ought to tell the truth about what happened.
Should can be used in place of ought to
- Given his height, he ought to play basketball.
- Given his height, he should play basketball.
- You ought to be kinder to animals and indects.
- You should be kinder o animals and insects.
Should not/shouldn’t can take the place ought not/oughtn’t
- You ought not to / oughtn't to have fed your fat dog so much.
- You should not / shouldn't have fed your fat dog so much.
- You ought not to / oughtn't to add so much salt to my soup.
- You should not / shouldn't add so much salt to my soup.
When ought to is used in a negative statement, the word not comes between ought and to: ought not to. It can be contracted as oughtn’t.Other negative words such as doesn’t, don’t, and didn’t are not used with ought to.
- We ought not to have spent so much time arguing.
- Not: We don't ought to have spent so much time arguing.
- You oughtn't to have been so rude to your grandfather.
- Not: You didn't ought to have been so rude to your grandfather.
Ought to in questions
In questions, the subject is placed between ought and to. Ought to is rarely used. The modal verb should is a better replacement for ought to in questions. Auxiliary verbs used in questions such as does and do are not used together with ought to in questions.
- Ought we to call her about the appointment?
- Not: Do we ought to call her about the appointment?
- Ought she to explain to us why her eyes are all red and swollen?
- Not: Does she ought to explain to us why her eyes are all red and swollen?
- Should we call her about the appointment?
- Should she explain to us why her eyes are all red and swollen?
The semi-modal used to is used to show a habitual action that was true in the past, but it no longer happens or is no longer true. It is used with the base form of a verb.
As indicated by the examples above, the semi-modal verb used to refers to the past and must remain like that. Its form should be changed by adding the auxiliary verb be before it.
Question and negative statement
Questions and negative statements using used to are formed in the same way as those using the main verbs. As used to is used to refer to a past habit, the questions and negative statements can only be used in the past tense. In questions, the past tense did is used before the subject, and the used of used to is changed the present tense use.
- "Did you cry for your mother when you were a child?" (Main verb in past tense)
- "Did you use to cry for your mother when you were a child?.
- "Did he use to get into a lot of trouble in his youth?".
- "I didn't use to cry for my mother when I was a child.".
- "He didn't use to get into a lot of trouble in his youth.".
When be used to is used before a gerund or noun phrase, it is used to mean to be accustomed to. Here, the auxiliary verb be comes before used to, and also before the word not in negative statements and the subject if it is a question.
- I am used to staying up late to watch movies on television..
- My family is used to keeping dogs as pets.
- We are used to the constant noise of the traffic outside.
- We were soon used to our new urban environment.
- I was not used to sleeping in the dark when I was a child.
- She was not (wasn't) used to spicy food.
- Are you used to living with your roommate's snoring?.
- Is the family used to the drunkard father?
As stated, used to is used for past habits. It is not used in a present form. The following examples show a habit that is still being practiced, and a shop that is still open for business.
- No: I used to cook turkey soup with a chopped-up stalk of celery.
Yes: I cook turkey soup with a chopped-up stalk of celery.
- No: There used to be a greengrocer's shop at the end of this row of shops.
Yes: There is a greengrocer's shop at the end of this row of shops.