1
Obligation by somebody else's decision.
2
A strong recommendation
3
Probability (35% or less)
4
asking someone to do something politely.
5
Used only in first person (I and we)
6
we use this modal verb to obligation and certainty.
7
Ability in past
8
Invitation, offer and polite request.
9
When we are talking about ability.
10
Permission, probability (50%)
