| Simple | Progressive | Perfect | Progressive |
| Present |
| I concentrate |
| you concentrate |
| he/she/it concentrates |
| we concentrate |
| you all concentrate |
| they concentrate |
|
| I am concentrating |
| you are concentrating |
| he/she/it is concentrating |
| we are concentrating |
| you all are concentrating |
| they are concentrating |
|
| I have concentrated |
| you have concentrated |
| he/she/it has concentrated |
| we have concentrated |
| you all have concentrated |
| they have concentrated |
|
| I have been concentrating |
| you have been concentrating |
| he/she/it has been concentrating |
| we have been concentrating |
| you all have been concentrating |
| they have been concentrating |
|
| Past |
| I concentrated |
| you concentrated |
| he/she/it concentrated |
| we concentrated |
| you all concentrated |
| they concentrated |
|
| I was concentrating |
| you were concentrating |
| he/she/it was concentrating |
| we were concentrating |
| you all were concentrating |
| they were concentrating |
|
| I had concentrated |
| you had concentrated |
| he/she/it had concentrated |
| we had concentrated |
| you all had concentrated |
| they had concentrated |
|
| I had been concentrating |
| you had been concentrating |
| he/she/it had been concentrating |
| we had been concentrating |
| you all had been concentrating |
| they had been concentrating |
|
| Future |
| I will concentrate |
| you will concentrate |
| he/she/it will concentrate |
| we will concentrate |
| you all will concentrate |
| they will concentrate |
|
| I will be concentrating |
| you will be concentrating |
| he/she/it will be concentrating |
| we are concentrating |
| you all will be concentrating |
| they will be concentrating |
|
| I will have concentrated |
| you will have concentrated |
| he/she/it will have concentrated |
| we will have concentrated |
| you all will have concentrated |
| they will have concentrated |
|
| I will have been concentrating |
| you will have been concentrating |
| he/she/it will have been concentrating |
| we will have been concentrating |
| you all will have been concentrating |
| they will have been concentrating |
|
