"My fork is in the bowl."
Translation:Garpu saya ada di mangkuk.
Hi Sherlene! 'Ada' and 'adalah' are not interchangeable here.
In this sentence, 'ada' is translated to 'is' and I assume you thought 'adalah" can be also translated to 'is' which is confusing. Giving examples would be the best way to explain their differences.
For 'ada': "Ibu saya ada di dalam dapur."
Translation: "My mother is in the kitchen."
For 'adalah': "Ibu saya adalah seorang koki."
"Citah adalah hewan tercepat di dunia."
"Pemenangnya adalah Sherlene."
Translation: "My mother is a chef."
"Cheetah is the fastest animal in the world."
"The winner is Sherlene."
Therefore, 'ada' is used for stating the subject's location (in the kitchen) and 'adalah' is used for describing the subject's unique feature. Hope this helps :)