Words for approximately

Hi What is the difference between Dàgài and zuŏyòu when talking about approximately? when would you use one over the other and which is more common to use? Thanks Jeff

Jeffrey 你好！ I shall do my best to explain the difference between 大概 and 左右. 大概 means 'general idea', 'approximately' or 'roughly' and is relatively abstract. For example, '我只知道个大概' which means 'I have only a general/rough idea' or ‘作一个大概的分析’ means 'to do a rough analysis'. 左右 means 'about' or 'or so' and is almost always preceded by a numeral. For example, ‘八点左右’ means 'around eight o'clock' and ‘一个月左右’ means 'a month or so'. The numeral may be in units of time, price, length etc. I hope this helps and keep up the good work! - Lin Ping