There is a difference
Can't...
Shouldn't...
Won't...
And
Don't...
Became
Can...
Should...
Will...
And
Do...
The
Moment
I
Met
You.
-'Words' By yours truly
"You can't be friends with a Slytherin! They're like a completely different species!" –Ron is skeptical.
"You shouldn't talk to him. His father is a Death Eater!" –Hermione is in shock.
"You won't be happy with him!" –Remus just wants what's best.
"Don't do it!" –Harry refuses to heed their advice.
A few weeks later
"We can meet again, after classes." –Draco is whispering, so the teachers don't yell.
"We should just tell everyone." –Harry is sick of hiding.
"I will, if you will." –Draco is ready, too.
Later still
"I do." –Is said together.