transform into negative.
1. look at the window.
2. i have bought two postcards and three envelopes.
3. they were able to cross the river.
4. the rifle was taken by the sergeant.
5. nick will go to the railway station.

1. Do not look at the window.

2. I have not bought two postcards and three envelopes.

3. They were not able to cross the river.

4. The rifle was not taken by the sergeant.

5. Nick will not go to the railway station.

1. Don’t look at the window.

2. I haven’t put no postcards in any envelopes.

3. They weren’t able to cross the river

4. The rifle wasn’t taken by the sergeant./The sergeant didn’t take the rifle.

5. Nick won’t go to the railway station.