质量不佳英文

Dear ***, I'm sorry to tell you the toy bears from the supplier are worse than before. So you'd better cancel the deal.

be of low quality

Video image quality is bad

网上购物坏处是质量无法保证，售后服务不好The disadvantage of online shopping is the quality can not guarantee, after-sales service is not good网上购物坏处是质量无法保证，售后服务不好The disadvantage of online shopping is the quality can not guarantee, after-sales service is not good

of poor quality/of low quality/inferioreg.inferior coal/faulty coal劣种煤eg.The book is of poor/low quality indeed.这本书质量真差这样翻译是最地道的英式译文，希望我的回答能对你有所帮助．

The quality of video is bad

Sometimes what you have bought is in poor quality, ....

The quality of the things you buy, is not always good.