その話はもうたくさんだ。

that (something or someone distant from the speaker, close to the listener; actions of the listener, or ideas expressed or understood by the listener); the; um...; er...; uh...

talk; speech; chat; story; conversation; discussions; negotiation; argument

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

now; soon; shortly; before long; presently; already; yet; by now; (not) anymore; further; more; again; another; the other; interjection used to strengthen expression of an emotion (often exasperation)

a lot; lots; plenty; many; a large number; much; a great deal; a good deal; enough; sufficient; enough; too many; too much

be; is; indicates past or completed action; indicates light imperative