Subject + 共 + Verb + Number + Measure Word + Noun
The word 共 (gòng) means "altogether" or "in total" and is used to express a combined quantity. It is placed before the verb or number to indicate the sum of something. For example, 共有两个儿子 means "have two sons in total."
我们班共有三十个学生。
wǒmen bān gòng yǒu sānshí gè xuéshēng.
There are thirty students in our class in total.
这次旅行共花了五千块钱。
zhè cì lǚxíng gòng huā le wǔqiān kuài qián.
This trip cost five thousand yuan in total.
他共写了三本小说。
tā gòng xiě le sān běn xiǎoshuō.
He wrote three novels in total.