1. The weather being fine, we decided to go for a walk.
Is that a very formal lg, only used in written works? Could be used in stories or personal letters?
2. On finishing work I left the office.
Is that he same as: "Having finished work I left the office"?
3. His being constantly tired worries me.
the same as : "It worries me that he is constantly tired"? When should we use this construction, the former one?
It's difficult for me to say whether a given expression sounds natural in everyday speech or is rather awkward . That's why I'm looking for the answer here.
Thank you
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