Answer:
I wish I had a pet dog
Step-by-step explanation:
Declarative sentences could be explained as those sentences which are used to make a frank and straightforward statements. This statements could be in the form of giving a factual statement or offering basic information usually expressed in simple terms and in most cases simple present tenses and a full stop.
The question given above ; How I wish i had a pet dog could be transformed into a declarative sentence by making the statement simply factual, that is ;
I wish I had a pet dog.