When having a conversation with a Deaf person, if you come to a point where you are not able to express yourself, there are a few acceptable ways to get your point across:
Writing: You can write down what you want to say on a piece of paper or a notepad. This is a common method used by hearing people in public places where it may not be appropriate to use sign language.
Gestures: You can use gestures to help convey your message. For example, if you are talking about a dog, you can make a barking gesture or if you are talking about something being hot, you can fan your hand in front of your mouth.
Visual Aids: You can use pictures or other visual aids to help get your point across. For example, if you are talking about a specific location, you can show a picture of that location.