Although gerunds are covered in a few different ways across a few CEFR levels in the English Grammar Profile, there is no entry given to the use of a gerund after ‘need’ as MODALITY which is listed by PEARSON: GSE 63 B2 ‘need’ with verbs in the gerund to express necessity. ‘need’ + Verb Phrase …
In general, ‘must’ is used to indicate that something is necessary or required. It is often used in situations where there are rules or regulations that need to be followed. For example, an employee must follow certain guidelines when using company resources. Similarly, a patient must provide accurate information to their doctor in order to receive proper treatment.
In the English Grammar Profile, C1 point 205 in MODALITY is defined as: PAST, NEGATIVE: ‘needn’t have’ + ‘-ed It means that somebody did something, but it was not necessary. Also, note that uncontracted ‘not’ is possible. Here are two examples: You needn’t have come so far, Asgardian. listen In fact, she need not have hurried. TED Well, we needn’t have worried. A search in iWeb: …
Here’s an example of an infinitive passive structure. He said it was the summation of the parts working together in such a way that nothing needed to be added, taken away, or altered. listen The English Grammar Profile B1 point 4 in the category of passives is defined as: an infinitive after a limited number of forms including ‘going to’, ‘have to’, ‘need to’, ‘want to’. *Note that Pearson lists this as: GSE 59 B2 …
Affirmative must questions are questions that use the modal verb must in the affirmative form. The modal verb must expresses obligation or necessity. In affirmative must questions, the subject of the verb must is inverted, meaning that the subject comes before the verb. For example:
Must I do my homework?
Must you go now?
Must we help them?
In these questions, the speaker is asking the listener if they are obliged or required to do something. The answer to these questions can be yes or no.