My question is how to change the taste of sweet potatoes into regular potatoes as my younger siblings don't like it whenever I cooked they leave dining table without finishing.Is there any trick to make sweet potatoes to the regular potatoes?
No, they are 2 different things.
How are you preparing them ?
Have you tried different ways of cooking them ? boiled, roasted, mashed, fried... ?
You could try mixing them up with regular potatoes.
When making mashed potatoes, add some of the sweet potatoes to the mix, start with a little bit, then increase ratio of sweet to regular potatoes.
White potatoes and sweet potatoes are very different varieties of tuber, you can't get rid of the sweetness and distinctive flavor of the sweet potato. If there's something in particular your family doesn't like then you can work on that, you can also try the LoB (Lots of Butter) technique, or you can try using them in a dish like sweet potato pie or a curry. At the end of the day if they just don't like sweet potatoes then it may be better to just make something they do like.
I agree with Max - you cannot change the taste of sweet potatoes to make them taste like regular potatoes BUT you can make oven-baked sweet potato fries and they will taste just as good ( or better because of all those amazing vitamins and minerals in the sweet potato) as baked potato fries. Cut the sw. potatoes lengthwise and drizzle oil and salt ( you only need very little, if at all) and bake in the oven for 45 minutes, checking to make sure they do not burn. Your siblings might just ask for more! Good luck!