You hear a commercial for chocolate chip cookies. This is their claim.
You chose not to move to Hollywood to follow your dream of being an actor. Your friend asks you this many years later.
You're being asked what color shirt a person was wearing. You think it was blue, but you say this because you're not 100% sure.
You were planning to send an email to some friends inviting them to go out for dinner. Now you're not sure if you sent it. Uncertain, you say this.