Answer: He should repent and seek divine forgiveness and it is necessary for him to observe the Qadha of the fasts which he has left out. As for kaffara (penalty), the details are as follows:
If a person breaks his fast by eating or drinking or sexual intercourse without knowing that he must fast or was certain that fasting is not obligatory on him or broke his fast due to inculpable ignorance (ignorance out of innocence), it is not obligatory to give kaffarah (penalty). In case, however, he was guilty of not learning the rules, then kaffara is obligatory on him, as an obligatory precaution.
In case he broke his fast and was fully conscious of his duty to observe fast or that he was aware that what he is doing invalidates the fast, kaffara becomes obligatory. The kaffara is to feed sixty poor even if he has broken his fast with something haram.
If he knew that it was necessary to observe Qadha in the same year but he did not observe the Qadha till next Ramadhan, he should give 750 grams of food stuffs (such as flour, bread, noodles or date etc.) as kaffara for each day.
If a person cannot observe the Qadha due to illness or other problems that hinder him from observing the Qadha, he should leave a Will asking his relatives to observe the Qadha on his behalf.