| ACTIVE VOICE |
PASSIVE VOICE |
| The researchers test the material. |
The material is tested by the
researchers.
The material is tested. |
| The researchers are testing the
material. |
The material is being tested
by the researchers.
The material is being tested. |
| The researchers will test the
material. |
The material will be tested by
the researchers.
The material will be tested. |
| The researchers should test the
material. |
The material should be tested
by the researchers.
The material should be tested. |
| The researchers should have tested
the material. |
The material should have been tested
by the researchers.
The material should have been tested.
|
| The researchers tested the material. |
The material was tested by the
researchers.
The material was tested. |
| The researchers have tested the
material. |
The material has been tested
by the researchers.
The material has been tested. |