| Simple | Progressive | Perfect | Progressive |
| Present |
| I ascertain |
| you ascertain |
| he/she/it ascertains |
| we ascertain |
| you all ascertain |
| they ascertain |
|
| I am ascertaining |
| you are ascertaining |
| he/she/it is ascertaining |
| we are ascertaining |
| you all are ascertaining |
| they are ascertaining |
|
| I have ascertained |
| you have ascertained |
| he/she/it has ascertained |
| we have ascertained |
| you all have ascertained |
| they have ascertained |
|
| I have been ascertaining |
| you have been ascertaining |
| he/she/it has been ascertaining |
| we have been ascertaining |
| you all have been ascertaining |
| they have been ascertaining |
|
| Past |
| I ascertained |
| you ascertained |
| he/she/it ascertained |
| we ascertained |
| you all ascertained |
| they ascertained |
|
| I was ascertaining |
| you were ascertaining |
| he/she/it was ascertaining |
| we were ascertaining |
| you all were ascertaining |
| they were ascertaining |
|
| I had ascertained |
| you had ascertained |
| he/she/it had ascertained |
| we had ascertained |
| you all had ascertained |
| they had ascertained |
|
| I had been ascertaining |
| you had been ascertaining |
| he/she/it had been ascertaining |
| we had been ascertaining |
| you all had been ascertaining |
| they had been ascertaining |
|
| Future |
| I will ascertain |
| you will ascertain |
| he/she/it will ascertain |
| we will ascertain |
| you all will ascertain |
| they will ascertain |
|
| I will be ascertaining |
| you will be ascertaining |
| he/she/it will be ascertaining |
| we are ascertaining |
| you all will be ascertaining |
| they will be ascertaining |
|
| I will have ascertained |
| you will have ascertained |
| he/she/it will have ascertained |
| we will have ascertained |
| you all will have ascertained |
| they will have ascertained |
|
| I will have been ascertaining |
| you will have been ascertaining |
| he/she/it will have been ascertaining |
| we will have been ascertaining |
| you all will have been ascertaining |
| they will have been ascertaining |
|
