I wonder what's the purpose of 了 in combination of "must, have to" verbs. Here are some examples:
我得把今天的练习做了。 I know without 了 it would mean "I must do today's exercises". But I don't know what changes does the particle 了 bring here? Is this 了1 or 了2?
我该回去了。 Without 了 it would mean "I must return". But I don't know how to translate this sentence with 了.
您不要出来了。 Without 了 it would mean "You shouldn't come out". What's the difference between the sentence above with "您不要出来".