你昨天睡得好吗？ Nǐ zuótiān shuì de hǎo ma?
Verb + 得 + complement → shows degree or manner of the action. So basically, “得” = shows the degree or quality of the action.
你汉语学得怎么样？Nǐ Hànyǔ xué de zěnme yàng?
is used to link a verb with a word that describes how well or to what extent the action is done.
你老公做饭做得好吃吗？Nǐ lǎogōng zuòfàn zuò de hǎochī ma?
Verb + 得 + complement → shows degree or manner of the action. So basically, “得” = shows the degree or quality of the action.