How does Achebe create a "new English" with his use of language in "Civil Peace"?

He fills his English with Igbo language patterns and rhythm.
He creates a completely new language, which he calls "new English."
He writes in Igbo and instills his writing with British proverbs and idioms.
His language, aside from using English, is stripped of all British colonial influence.

Question

How does Achebe create a "new English" with his use of language in "Civil Peace"?

He fills his English with Igbo language patterns and rhythm.
He creates a completely new language, which he calls "new English." 
He writes in Igbo and instills his writing with British proverbs and idioms.
His language, aside from using English, is stripped of all British colonial influence.