Can generic mark becomes descriptive?

based on the spectrum of distinctiveness generic marks are trademarks that incapable of distinctiveness because they consist of names of products are known. i read some literatures that explains that generic marks can also be considered "descripttive" but incapable of ever achieving secondary meaning such as continous usage and famous and well-known marks. is it possible for generic marks to be transformed into descripttive marks? any example?

thanks in advance