The Presiding Officer (or Deputy Presiding Officer) decides who speaks in chamber debates and the amount of time for which they are allowed to speak. Normally, the Presiding Officer tries to achieve a balance between different viewpoints and political parties when selecting members to speak. Typically, ministers or party leaders open debates, with opening speakers given between 5 and 20 minutes, and succeeding speakers allocated less time. The Presiding Officer can reduce speaking time if a large number of members wish to participate in the debate. Debate is more informal than in some parliamentary systems. Members may call each other directly by name, rather than by constituency or cabinet position, and hand clapping is allowed. Speeches to the chamber are normally delivered in English, but members may use Scots, Gaelic, or any other language with the agreement of the Presiding Officer. The Scottish Parliament has conducted debates in the Gaelic language.