He is an expert in orthoepy, teaching pronunciation.

It is important to understand the importance of health.

In French, the partitive article plays a very important role.

The greater part of the time is spent on work.

This project was partially successful.

The company decided to change its policy in order to adopt a new strategy.

The government decided to change the course of its economic policy.

He decided to undergo sex change surgery.

He decided to undergo sex change surgery.

He is an expert in computational linguistics and is involved in the development of artificial intelligence.