The subjunctive mood in English is used to form sentences that do not describe known objective facts, but rather wishes or hypothetical suppositions. These include statements about one's state of mind, such as opinion, belief, purpose, intention, or desire. The subjunctive mood, such as She suggests that he speak English, contrasts with the indicative mood, which is used for statements of fact, such as He speaks English.
This is a companion discussion topic for the original entry at http://grammarerror.com/tags/subjunctive-mood