Gunakan which/who/that untuk memberikan penjelasan terkait suatu hal
Which digunakan untuk benda saja
Who digunakan untuk orang saja
That digunakan untuk benda atau orang
Example:
The solution which is not effective cannot deal with several problems that may occur.
The mall which is located near my house has many interesting cafes.
The people who work with me are very friendly.
The boss who has great leadership helped advance the company in many ways.
The expense of research that is very high is a risk the company must take.
The government that does not take care of the citizen's welfare is not worth supporting.