Solution:
The English language is distinguished by eight parts of speech. They can be categorised as nouns, adjectives, pronouns, verbs, adverbs, conjunction, proposition, and interjection. Modal auxiliaries or modals are verbs used with another verb to express a variety of meanings. Based on the meanings expressed, modal auxiliaries can be categorised into five types: modals that express permission, modals that indicate likelihood, modals used to give advice, modals that denote ability, and modal auxiliaries that denote obligation. “Can” is used to denote ability, power, possibility, or permission, and “could” is the past form of “can,” which can also be used to express possibility, request or permission. “Would” is the past form of “will,” which is often used to make a request. “Should” denotes moral duty or advice. So, the correct way to frame the sentence is, “Those children should be at school.”
