however

我很喜欢这个礼物，然而它太贵了。

I really like this gift; ___however, it's too expensive.

这本书很有趣，然而有点难懂。

This book is interesting; ___however, it's a bit difficult to understand.

我很累；不过，我仍然需要完成这项工作。

I am very tired; ___however, I still need to finish this work.