Ails

Ails is the third-person singular present tense form of the verb ail. To ail means to cause pain, trouble, or distress, or to suffer from illness. In its transitive sense, it can be used to indicate something causing harm; in its intransitive sense, it describes someone being sick or unwell.

The phrase "what ails you?" is a classic example, and it remains common in literature, older speech, or formal writing. In everyday modern English, speakers more often say "what's wrong with you?" or "what's the matter?" The verb is commonly used in medical, agricultural, and figurative contexts: "The drought ails the crops," "The patient ails with pneumonia."

The noun form "ail" is not standard in contemporary usage; the illness or health problem is more typically described with "illness" or "ailment." The form "ails" is used strictly as a verb and does not generally function as a noun. Related verbs include "afflict," "trouble," and "distress."

See also: ailment, illness, affliction.