You've been having lunch with a friend and just noticed that the skin around your fingernail hurts. This is what you say.
You've just finished giving a 15-minute presentation at an event for people to practice giving speeches in English. Now you want to give the audience a chance to ask you questions, so you say this.
You gave a presentation at an event for people to practice giving speeches in English. Now you've opened the floor for questions. A few different people have raised their hands to ask a question, and you need to pick one of them. You say this and ...
You come home after work, and your wife is cooking fish. You were able to smell it before you even came in the door. When you come in, you say this.