彼らはその体系を大変な思索と労力を費やして仕上げた。

tbd

They worked out the system with much thought and labor.

これは英語を、詳細に学習され厳密に適用されるべき文法と文構造の規則に従う体系とみなしている。

tbd

This sees English as a system obeying miles of grammar and sentence structure which have to be learned in detail and applied rigorously.