Colloquial writing: text written in a form close to spoken language (as opposed to classical or literary written style).
この小説は口語文で書かれているので読みやすい。
This novel is written in colloquial style, so it's easy to read.
昔の官報は文語文だったが、現代の解説は口語文で書かれている。
Old official gazettes were written in literary style, but modern commentaries are written in colloquial form.
学習者のために、古典の一部を口語文に直して解説した。
For learners, I converted parts of a classical text into colloquial writing and explained them.