Modal auxiliary verbs

Discussing difficult topics with families is not something we are necessarily prepared for, we [blank_start]may[blank_end] know the people around us love us, but going against what they expect from us is actually a different story. However, it is clear we [blank_start]must[blank_end] do so in a spirit of honesty and family love. If I had to talk to my family about a difficult issue that is private and only affects me, I [blank_start]might[blank_end] do it in such a way that nobody [blank_start]can[blank_end] judge me or disrespect my options. I think my private life, even if I were a minor is my own choice and families [blank_start]should[blank_end] be able to support and encourage our own development. If, on the other hand, the issue we need to discuss affects all of us, I know I must approach it with an open mind and a spirit of negotiation and compromise. I am not entitled to do things that [blank_start]would[blank_end] hurt the people I love, in those cases I should do my best to come to agreements for everybody’s sake.

What would be the right modal to complete the following sentence? During the quarantine, citizens ___________ wear a face mask when they are in public places.

What would be the right modal to complete the following sentence? My friend is really smart, she _____ speak 4 languages and does math in her head.

What would be the right modal to complete the following sentence? If it rains, I _______ not go out tonight, I prefer to stay indoors during cold weather.

Can is a modal auxiliary verb that expresses physical possibility and abilities

The modal Must expresses a probability of something happening.