to the extent unpaid ?

1. "to the extent unpaid" is a prepositional phrase functioning as adverb, also called adverbial phrase. (reference: to a certain extent = 在一定程度上)

question: To what extent?
answer: To the extent unpaid. (where "unpaid" is an adjective quantifying "extent")

Like adverbs of degree, the above adverbial phrase modifies the compound verb "should be recognised", providing information about how much of the subject (current tax) should be recognised.

The sentence could be understood as:
The unpaid portion of the current tax for current and prior periods should be recognised as a liability.

2. Same as 1, "to the extent that-clause" is an adverbial clause. The subsequent "that-clause" is a relative/adjectival clause quantifying "extent". It is also used to modify the verb "should be recognised".

The conjunction "except" is added in front of the above adverbial phrase to provide information about how much of the current tax should not be included to be recognised.





2012-07-15 11:33:35 補充：
typo: 2. Same as 1, "to the extent that-clause" is an adverbial phrase.

2012-07-15 11:48:17 補充：
Correction:

Actually, the "that-clause" should be an appositive clause. Appositive clause nornally follows an abstract noun and add information to it in the same manner as an adjective.

2012-07-15 12:37:24 補充：
Appositive clause normally follows an abstract noun and adds information to it in the same manner as an adjective.