I would like to ask if the following sentence is grammatically correct, if so, please kindly explain in detail since as far as I know, the "to do" pattern can only be used within a sentence but not as an independent part.Is it simply because it omits the subject and predicate? Thank you! If possible please give me an example,how you usually say it.

***Great, all right, to be earning your own dough.***

PS:it can tell from the translation that the above sentence is something a person said to someone who has not worked and earned money bofore.
Great, all right, to be earning your own dough.-- This sounds like a common enough utterance, but it is not a complete sentence. It does, as you say, need some sort of subject and finite verb to make it a grammatically complete sentence:

It is great, all right, to be earning your own dough.
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Thank you!

But what's the difference between

Appropriate ages to be doing........stuff? at http://au.answers.yahoo.com/question/index?qid=20110504032618AA7I4Sl


Appropriate ages to do .... stuff?

Appropriate ages to be doing..stuff -- This refers to what they are actually doing.

Appropriate ages to do .. stuff-- This refers to what they might potentially do,
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