I think a lot of time as we may mistake nosy behavior for being nosy when they are just being trying to be friendly,or maybe that person is lonely. 

由于网友没有提供更多语境，只能按照这句子分析。该句至少有两个语法问题：

1.as 多余，应删去。这样，think 后面是宾语从句。a lot of time 是宾语从句的时间状语。

2. are being trying  —— 错误。去掉 being。

修改后：

I think （that）a lot of time we may mistake nosy behavior for being nosy when they are just trying to be friendly, or maybe that person is lonely. 

（1）mistake nosy behavior for being nosy：介词 for 后面接动名词短语，动名词由系表结构 be + adj. 构成。

（2）or maybe that person is lonely 属于 when 从句的，与 they are just being trying to be friendly 并列。