В отрецательной форме 1 My goat is white.
2 The girl is in the garden.
3 My car is good.4 Your vase is on the table.
5 The frog is green.
6 Your pen is under the bed

Чтобы получить отрицание, нужно всего лишь добавить частицу not к вс глаголу is:

is + not = isn't (сокращение полной формы is not)

1 My goat isn't white.

2 The girl isn't in the garden.

3 My car isn't good.

4 Your vase isn't on the table.

5 The frog isn't green.

6 Your pen isn't under the bed.