【中文版】

货币数量主要由货币发行量、货币流通速度和商业交易规模等因素决定。

首先，货币发行量是决定货币数量的关键因素。货币发行量由国家或中央银行决定，通常会根据国家的经济状况和货币政策进行调整。例如，在经济繁荣时期，货币发行量可能会增加以适应经济增长的需求；而在经济衰退时期，货币发行量可能会减少以控制通货膨胀。

其次，货币流通速度也会影响货币数量。流通速度是指货币在市场上的周转速度，它受到社会习惯、支付方式、信用体系等因素的影响。如果人们更倾向于使用现金进行交易，那么货币流通速度就会降低；如果人们更倾向于使用电子支付方式，那么货币流通速度就会提高。

最后，商业交易规模也会影响货币数量。商业交易规模包括商品和服务的生产、交换和消费等方面。如果生产规模扩大、交换活动增加或消费需求增长，那么货币数量就会增加；反之则会减少。

总之，货币数量是由货币发行量、流通速度和商业交易规模等多种因素共同决定的。这些因素相互作用、相互影响，共同决定着货币数量的变化。

【英文版】

The quantity of currency is mainly determined by factors such as the amount of currency issued, the speed of currency circulation, and the scale of commercial transactions.

Firstly, the amount of currency issued is a key factor determining the quantity of currency. The amount of currency issued is determined by the state or central bank, and is usually adjusted based on the country's economic situation and monetary policy. For example, during periods of economic prosperity, the amount of currency issued may increase to meet the needs of economic growth; while during periods of economic recession, the amount of currency issued may decrease to curb inflation.

Secondly, the speed of currency circulation also affects the quantity of currency. The speed of circulation refers to the turnover rate of currency in the market, which is influenced by social habits, payment methods, credit systems and other factors. If people tend to use cash for transactions, the speed of currency circulation will decrease; if people tend to use electronic payment methods, the speed of currency circulation will increase.

Finally, the scale of commercial transactions also affects the quantity of currency. The scale of commercial transactions includes the production, exchange, and consumption of goods and services. If the production scale expands, exchange activities increase, or consumer demand grows, then the quantity of currency will increase; otherwise it will decrease.

In summary, the quantity of currency is determined by multiple factors such as the amount of currency issued, the speed of circulation, and the scale of commercial transactions. These factors interact and influence each other to determine changes in the quantity of currency.