"Always" doing something - difference between 一直，总是，老是...
This has been been confusing me. I am never sure when to use 一直，总是 or老是... I have learned by now that 老 is often being used when something has a negative connotation. But what to use for the following:
I have always been very tall.
She always knows where to go.
They're always talking in class.
I've always wondered ...
He's always smiling.
Does anyone know a good way to distinguish between those?
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