1) About half of a month.
大概半个月吧。
2) first half of the month
前半个月
3) Five Months Older
大五个月
4) Perhaps it was the day before yesterday.
大概是前天吧。
5) That is about the size of it.
这大概差不多吧。
6) Snake: Must have missed that one.
大概错过了吧。
补充资料：大概
副词。表示不很精确的估计：老校长大概五十来岁｜乌云满天，大概要下雨了。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条