Here are some examples:
* Hindi siya nagalit, bagkus ay ngumiti siya. (He didn't get angry, rather he smiled.)
* Gusto kong kumain ng pizza, bagkus ay bibili ako ng ice cream. (I want to eat pizza, but instead I will buy ice cream.)
* Hindi siya nag-aaral ng mabuti, bagkus ay naglalaro siya ng computer. (He doesn't study well, instead he plays computer games.)
In essence, "bagkus" is used to introduce a contrasting idea or action that replaces the previous one.