grammer

In this sentence "influencing" is a verbal (present participle) and functions as an adjective to describe the liver. Although "influencing" can also be a gerund (another form of verbal ), and therefore does not follow an auxiliary verb, it is not functioning as a gerund in this sentence, because "gerund" is a noun, which isn't the case here.

The sentence can be presented in four ways:
(1) The liver regulates shen, influencing emotional response in particular. (*influencing as a present participle verbal, heading up an adjective phrase).
(2) The liver regulates shen, with influence on emotional response in particular. (*influence as a noun within the prepositional phrase headed by "with").
(3) The liver regulates shen, and influences emotional response in particular. (*inlluences as a main verb within the "and" clause).
(4) The liver regulates shen, and has influence on emotional response in particular. (*influence as a noun, after the auxiliary verb "has", which is used as a main verb within the "and" clause".)

Note that example one and two involve one main sentence and one main verb, with a phrase, while the other two examples involve a main clause and a sub-ordinated clause, with one verb in each clause.

Also take note that "influence" is used either as a "transitive verb" or as a "noun", and can only be followed by a preposition when used as a noun.

In the original sentence, some people will argue that "influencing" is used as a gerund. I don't agree but am not certain. If the argument is correct, "influencing" will be a noun and will justify the use of the preposition "on" after it.





2010-12-28 09:06:41 補充：
In example 3, we don't use "is influencing" because it will become a "continuous tense" and won't match the main clause.

Dunno about this posh grammar stuff but influence when used as a verb is followed by in not on so the sentence is wrong. IMO influence doesn't collocate with emotional response either but I can't be sure..

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