Sentence 1。但是, + Sentence 2
但是 (dànshì) can begin a new sentence to signal contrast with the previous statement. In this usage, it functions as a transitional word linking two separate sentences, similar to starting a sentence with "However" in English.
我觉得你说得有道理。但是,我们也要考虑其他人的感受。
wǒ juéde nǐ shuō de yǒu dàolǐ. dànshì, wǒmen yě yào kǎolǜ qítā rén de gǎnshòu.
I think what you said makes sense. However, we also need to consider other people's feelings.
这个方案听起来不错。但是,执行起来可能会有困难。
zhège fāng'àn tīng qǐlái búcuò. dànshì, zhíxíng qǐlái kěnéng huì yǒu kùnnán.
This plan sounds good. However, it might be difficult to implement.
他确实很有才华。但是,态度决定一切。
tā quèshí hěn yǒu cáihuá. dànshì, tàidù juédìng yíqiè.
He is indeed very talented. However, attitude determines everything.