Question

my favourite fruit is mango(change into interrogative form)

Answer 1

The given sentence can be made into interrogative sentence in the following two ways:

Is my favourite fruit mango?

Is mango my favourite fruit?

Any statement that has the auxiliary verb given in it, can be formed into interrogative by placing it in front of the subject. In this sentence we placed the auxiliary 'is' in front of the subject 'my favourite fruit', and then in front of ' mango' in the second option.