I heard that a person can make a vow that if his wish is granted he would keep a certain number of fasts or pray a certain amount of nafals. Now I have said that on a number of occasions and as a result am now required to keep 30 fasts and pray 70 nafals. Is there another way I could get around this?

Making vows of worship for the fulfillment of certain wishes was never the way of the Prophet (sws) and Companions (rta). It means that a person is imposing a condition to carry out certain virtuous deeds and also burdening himself with some thing which may ultimately be very difficult to fulfill, as seems to be the case with you. Worship done in this manner may also adversely affects a person’s relationship with his Creator. It becomes more of a mechanical act done often done in disregard to the spirit of worship. Worship should be done from the willingness of the heart and from the eagerness of the soul, otherwise it will fail to reap the real benefit it carries: purification of the inner self. In fact, worship done if one’s wish is not granted may at many times be more beneficial in achieving this end.

The correct way in this regard is to pray to the Almighty that a certain wish be granted. If the wish is granted, a person should express his gratitude by letting his feelings take their own course and manifest themselves in whatever form of worship at that particular time. Also, the quantity of worship does not matter in such cases: it is the quality that really counts.