Correct use of phrases

Entering Form Four, if one chose to study in the Science stream, it was as good as studying in an English school because General Mathematics, Additional Mathematics, General Science, Pure Science, Chemistry, Physics and Biology were taught in English.

"Entering Form Four" in the above sentence (which is taken from an article of a popular national English daily) can be a noun phrase or an adjective phrase.

If it is a noun phrase, the phrase has rendered the following preparatory pronoun 'it' redundant; but if it is an adjective phrase, this participial phrase appears to qualify the said pronoun 'it' making its description out of place.

To be grammatically sound, the sentence needs to be reworded as "If one entering Form Four chose to study in the Science stream, it was as good as studying in an English school because General Mathematics, Additional Mathematics, General Science, Pure Science, Chemistry, Physics and Biology were taught in English."

Of course, it can also be "If one chose to study in the Science stream when entering Form Four, it was as good as studying in an English school because General Mathematics, Additional Mathematics, General Science, Pure Science, Chemistry, Physics and Biology were taught in English."

For participial phrases, please see my earlier posting of December 21, 2009.