"Now that" - What does this mean?

[Duc]

Hello,
Please look at the following sentence. I have just read it in a letter:
''Now that I am able to write to you....''
I wonder what ''now that'' means because I can't find them in all my dictionaries.
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Don't see your shade think you are great

[Alan]

Hi,

This means: 'Since the moment has now arrived when I am able....'

Alan
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English as a Second Language
You can read my ESL story Present Simple