改善 / 改进 / 改革【gǎishàn / gǎijìn / gǎigé】

改善, 改进 and 改革 all change something for the better. 改善 makes conditions better, 改进 makes a way of doing things better, and 改革 changes a system at its base.

改善 – conditions

The object of 改善 is a state you live in or with: 生活, 条件, 环境, 关系, 情况. It assumes the state was poor and is now less so.

改进 – methods and products

改进 goes with how something is done or made: 方法, 技术, 工作, 设计, 产品. Something already works, and it is made to work better.

改革 – systems

改革 changes structures – 制度, 体制, the economy, education – and it often stands as a noun after the field it changes: 经济改革, 教育改革. It is too large a word for one person's habits or a single product.

Choosing the wrong object

• × 改进生活 → 改善生活
• × 改善学习方法 → 改进学习方法
• × 改革我的学习方法 → 改进我的学习方法

For a person's own skill, the everyday word is 提高: 提高中文水平.