一共

一共 (yígòng) is the adverb meaning 'in total, altogether, in all' — used to give a summed amount of money, people, items, or time. It typically appears right before the verb (usually 是 'is' or a verb of having / counting) and the totalled quantity: 一共多少钱 ('how much in total'), 一共有十个人 ('there are ten people in total'). Two things English speakers often miss.

First, 一共 is the go-to word at cashiers and counters — every shopkeeper in China will say 一共 X 块 when telling you your total. Second, 一共 differs from 总共 (zǒnggòng) only slightly: 总共 is a touch more formal / written but they are interchangeable in most everyday contexts. Note the tone change: 一 is read yí (second tone) before the fourth-tone 共.