used after a statement to indicate an emphatic or ironic negative

(history) The war from 1914 to 1918 between the Entente Powers of the British Empire, Russian Empire, France, Italy, the United States and other allied nations, against the Central Powers represented by the German Empire, Austria-Hungary, the Ottoman Empire, and Bulgaria.

An affirmation of affection or deep caring, especially to a family member. / An affirmation of romantic feeling to a lover or spouse. / A platonic expression of strong inclination or liking to a friend.

I believe that is the case, but am not certain.

A phrase used in response to a question or command in which the target person does not know the answer to or how to respond.

Indicates that the speaker is not understanding the current subject or situation.

(chiefly Britain, idiomatic) I am mistaken; I thought that what I said (or wrote) was true, but I have just realised that it is not.

(idiomatic) An exclamation of great surprise.

Expression of hatred, or intense disdain or dislike directed at someone. Some might invoke this phrase without literal implication, such as unselectively and uncontrolledly directing the phrase to innocent surrounding people as a result of difficult life circumstances, or jokingly in reponse to being pranked. Such uses should be avoided, however.

A request for information.