This one-page visual organizer helps students understand when to use either verb.
Here is how I present the concept of two verbs in French and one verb in English.
Step one, without showing the visual organizer:
I always engage the class in a conversation in English about how we use "I know" in English. From that point on I encourage my students to think about what they mean when they say "I know", and invariably they talk about information and personal experience. The conversations are always lively, students enjoy expressing deeper thoughts and debating about the meaning of this powerful statement: I know.
Step two: with the visual organizer: I ask the students to compare the two columns, step by step, and to think about which verb they would use to express their ideas.
This mini-lesson takes between thirty minutes to forty five minutes. Feel free to extend the first step in order to give your students more opportunities to voice their thoughts. The more you engage them in this meta-cognitive process the better they retain the concept.
Be sure to try other "All you need to know about..." resources that I have posted.