請問這兩個英文句子有沒有錯誤

不好意思請問一下 (1) Some people may say that it is the sweetest part of love; however, I have to say, it is the most harmful thing to our heart however前面如果改成"," 可以嗎?? (2)Love brings us a lot of emotions. Sometimes is brings us happiness, and sometimes upset, of which constantly make a positive-negative... show more 不好意思請問一下

(1)
Some people may say that it is the sweetest part of love; however, I have to say, it is the most harmful thing to our heart

however前面如果改成"," 可以嗎??

(2)Love brings us a lot of emotions. Sometimes is brings us happiness, and sometimes upset, of which constantly make a positive-negative emotional circulation in our daily life.

這樣寫有沒有地方有錯呀?!

感恩捏~~
Update: 那請問該怎麼修改呢?? 尤其是第二句 我想知道該怎麼改
謝啦
3 answers 3