Aggressive is defined as being ready or likely to attack, while assertive is defined as showing a confident and forceful personality .
When you’re assertive, you are authoritative, you look people in the eye at their level, you use a respectful tone, and you calmly make declarative statements.
You use a tone that’s caring and non-destructive, not one that’s dictatorial and “my way or the highway.”
Basically, you bring the threat level down. Try it no matter what tone everyone else is using and you just might find that your point comes across even stronger.