The modal verbs of English are a small class of auxiliary verbs used mostly to express modality (properties such as possibility, obligation, etc.). They can be distinguished from other verbs by their defectiveness (they do not have participle or infinitive forms) and by their neutralization (that they do not take the ending -(e)s in the third-person singular). The principal English modal verbs are can, could, may, might, must, shall, should, will and would. Certain other verbs are sometimes, but not always, classed as modals; these include ought, had better, and (in certain uses) dare and need. Verbs which share only some of the characteristics of the principal modals are sometimes called "quasi-modals", "semimodals", or "pseudomodals".
The (listen) is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners or readers. It is the only definite article in English. The is the most commonly used word in the English language, accounting for seven percent of all words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of either genders. The word can be used with both singular and plural nouns and with a noun that starts with any letter. This is different from many other languages which have different forms of the definite article for different genders or numbers.
An error (from the Latin error, meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake. In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behaviour.