Count on
Definition 1 of 2
Pro Tip 1/3Personal Reliability
Used when expressing trust in someone's consistent support or action. 
I can always count on Sarah to deliver the reports on time.
Pro Tip 2/3Emotional Support
Indicates confidence in someone providing comfort or a listening ear. 
During difficult times, you can count on your family.
Pro Tip 3/3Assurance Cue
Signals absolute certainty to someone about receiving help or support. 
Don't worry about the event, you can count on me for the preparations.