| Simple | Progressive | Perfect | Progressive |
| Present |
| I stack |
| you stack |
| he/she/it stacks |
| we stack |
| you all stack |
| they stack |
|
| I am stacking |
| you are stacking |
| he/she/it is stacking |
| we are stacking |
| you all are stacking |
| they are stacking |
|
| I have stacked |
| you have stacked |
| he/she/it has stacked |
| we have stacked |
| you all have stacked |
| they have stacked |
|
| I have been stacking |
| you have been stacking |
| he/she/it has been stacking |
| we have been stacking |
| you all have been stacking |
| they have been stacking |
|
| Past |
| I stacked |
| you stacked |
| he/she/it stacked |
| we stacked |
| you all stacked |
| they stacked |
|
| I was stacking |
| you were stacking |
| he/she/it was stacking |
| we were stacking |
| you all were stacking |
| they were stacking |
|
| I had stacked |
| you had stacked |
| he/she/it had stacked |
| we had stacked |
| you all had stacked |
| they had stacked |
|
| I had been stacking |
| you had been stacking |
| he/she/it had been stacking |
| we had been stacking |
| you all had been stacking |
| they had been stacking |
|
| Future |
| I will stack |
| you will stack |
| he/she/it will stack |
| we will stack |
| you all will stack |
| they will stack |
|
| I will be stacking |
| you will be stacking |
| he/she/it will be stacking |
| we are stacking |
| you all will be stacking |
| they will be stacking |
|
| I will have stacked |
| you will have stacked |
| he/she/it will have stacked |
| we will have stacked |
| you all will have stacked |
| they will have stacked |
|
| I will have been stacking |
| you will have been stacking |
| he/she/it will have been stacking |
| we will have been stacking |
| you all will have been stacking |
| they will have been stacking |
|
