You must believe in love.

[Daniela Aguirre Macias]

How do you decide when to use 'must' or 'should' in a sentence? Can you share an example where one is more appropriate than the other, either from your own experience or from a song lyric?

I'm not an expert in this area, but here are my thoughts:
The modal verbs must and should are often used to convey different levels of urgency or advice. Must indicates a strong necessity or a rule, while should is used for suggestions or mild advice. For example, in a song lyric like "You must believe in love", the verb must shows a stronger sense of belief being required. On the other hand, "You should try to be happy" is a gentler recommendation. Think about how the context around these verbs influences their meaning and strength. I'd really appreciate hearing your thoughts or examples to help clarify this!

 

[probus]

I think you've pretty much nailed it @Daniela Aguirre Macias. Must is definite, leaving no room for doubt, as in "I really must get home now." Should is much weaker. If I say "I really should get home now", I may or may not actually head for home right away.

Since your mother tongue is Spanish this may help:

Think of must as equivalent to "tener que" and should to "deber".

 

[jutfrank]

Think about how the context around these verbs influences their meaning and strength.

Yes, this is exactly right. If you'd like to provide some real examples of use, with plenty of context to reveal the meaning, we'll be happy to do a more in-depth analysis.