增加30英语怎么说

"增加30" 的英语表达是 "increase by 30"。
其中 "increase" 是动词，意思是 "增加"；"by" 是介词，意思是 "由"；"30" 是数字，意思是 "30"。
例如：
The temperature will increase by 30 degrees. (温度将会增加30度。)
Sales have increased by 30% this quarter. (本季度销售增长了30%。)
The number of visitors to the museum has increased by 30 this month. (这个月博物馆的游客人数增加了30人。)
"increase" 是英语中常用的动词，来源于拉丁语 "incrementum"，意思是 "增加"，"增长"。