CASE STUDY TWO : We have already discussed on the previous pages that a clause is built from one main clause and one sub clause. To determine types of clauses (noun, adverb or adjectives) depends on the sub clause. When the sub clause denotes an adjective characteristic, the clause is called "Adjective Clause". This is the same as adverb or noun clause.
After I watched the film, I went to sleep.
Here, the sub clause is /After I watched the film/ because there is a conjunction /after/ is being used. Remember that Main Clause or a full sentence can be changed into Sub clause by adding a conjunction at the beginning or before the subject.
We can modify adverb of clauses and change it into phrase. To do that, we have to know which sub clause and main clause is. Here, Only sub clause will be changed, not main clause.
To change the sub clause into phrase then the subject of the sub clause must be the same as the subject in the main clause.
While I was reading a newspaper, I found my photograph on it.
After that, omit the subject/I/ and the be /was/ in the sub clause to change it into a phrase.
While reading a newspaper, I found my photograph on it.
When the sub clause structure is in non progressive tense, Omit the subject and change the verb into present participle.
After I watched the film, I went to sleep. (Non progresive sub clause). So, It becomes; After watching the film, I went to sleep.
The point of modification here is the subject. So, the subject plays important roles and decides whether the sub clause can be changed into a phrase (or not). The conclusion is the change only occurs when the subject in the sub clause is the same as the subject in the main clause.
This sub clause below can also be changed. e.g. While Rudy climbed the tree, he found so many birds around him --> While climbing the tree, he found so many birds around him. Take notice that the subject /rudy/ denotes the subject /he/ in the main clause. It is a matter of clothing!
So, It is impossible to change the sub clause like this follows!
While the teacher was discussing the lessons with the students, Marry entered the classroom. Why?
It is because the subject /teacher/ in the sub clause is NOT the same as the subject /mary/ in the main clause.
To learn back about a structure of adverb, please click here.