Here are some examples:
* "Je me sens mal." (I feel bad.)
* "Il y a quelque chose de mal." (There is something wrong.)
* "Le temps est mal." (The weather is bad.)
* "C'est mal fait." (It's poorly done.)
It can also be used to describe physical pain or sickness:
* "J'ai mal à la tête." (I have a headache.)
* "Il est malade." (He is ill.)
The meaning of "mal" will depend on the context of the sentence.