1
I have to wear a uniform to work.
To express this sentence, establish the context of your job by signing *work*, then use the 'U' handshapes sliding down your chest to indicate the specific clothing required. Finish by pointing to yourself and signing *must* to show the obligation.
2
The police officer's uniform is blue.
Start by signing *police* by tapping a 'C' handshape on your upper chest. Next, use the *uniform* sign by sliding your 'U' hands down your torso, and conclude by shaking a 'B' handshape to describe the color *blue*.
3
Do students wear uniforms at that school?
Ask this by signing *school* and *student*, then perform the *uniform* sign with the simultaneous downward 'U' hand motion. Remember to raise your eyebrows and lean forward slightly to indicate a yes/no question.