You are going to school and you meet your friend on the way. He/she is looking at the phone and didn't see the red traffic light. Make a conversation with him/her and talk about the following information: 

- giving warning

- asking him/her what he/she did

- giving advice on traffic

Remember to use Look out / look out for to give warning and ought to / shouldn't + V1 to give advice. 

Start and end the conversation properly.