thanghnvn Wrote:E is wrong because
"doing" can be used in one of the following cases
- noun doing
- before a clause, we need comma before the main clause
learning english, I feel happy
- after a clause, we nned a comma before "doing"
I learn English, feeling happy.
there is no other cases in which "doing" is used
in the cases 2 and 3, "doing' can modify the subject or modify the main verb and refer to the subject.
is my thinking correct?
in your cases #2 and #3, the modifiers can't modify
only the subject; there must be some sort of relevance to the action of the verb.
in other words, if this kind of modifier accurately describes the subject but has nothing to do with the verb/action, then it's incorrect.
e.g.
Standing almost seven feet tall, Wade is one of the best math students in the class.--> incorrect; even though "standing almost seven feet tall" describes "Wade", there is no reasonable connection between wade's height and his math prowess
vs.
Standing almost seven feet tall, Wade is one of the most physically imposing students in the class.--> correct; the modifier applies to wade and also has an obvious relationship to the following clause.
--
by the way, i can also think of a fourth usage of this kind of modifier: it may follow a noun (i.e., NOT a clause), in which case it describes that noun—but, again, not just the noun. as before, it must describe the entire following action in some obvious way (= obvious enough not to require further explanation!).
e.g.
Wayne, frantically waving his arms, tried to attract the attention of the pilot flying overhead.(correct example)
--> in this sentence, note that (a) the modifier "waving..." describes wayne, and also that (b) there is a clear relationship between the action of the modifier and the action of the clause that it modifies.