1、然而，很可惜的是…

However, it is a pity that 从句

例：然而，很可惜的是他总是临时抱佛脚。

However, it is a pity that he should always cram at the eleventh hour.

2、换言之…

in other words=to put it differently

例：换言之，我会尽最大的努力达成我的目标。

In other words, I will try my best to attain (gain, live up to) my goal.

3、别人可能认为这是事实，但我不是。我认为…

It may be true as assumed by others, but I don't. I believe that 从句

例：别人可能认为这是事实，但我不是。我认为只要有坚定的决心和意志，胜利终究会属于你的。

It may be true as assumed by others, but I don't. I believe that if you have strong determination and perseverance, the success will certainly come to you in the end.

4、从此之后，我发现…

Ever since then, I have found that 从句

例：从此之后，我发现微笑是面对生活中任何挫折的最佳方式。

Ever since then, I have found smile is the best way to avoid any possible conflicts in our daily lives.