| singular | plural |
| Infinitive | | |
| concentrate | |
| present simple | | |
| 1 | I concentrate | we concentrate |
| 2 | you concentrate | you concentrate |
| 3 | he/she/it concentrates | they concentrate |
| past simple | | |
| 1 | I concentrated | we concentrated |
| 2 | you concentrated | you concentrated |
| 3 | he/she/it concentrated | they concentrated |
| future simple | | |
| 1 | I will/shall concentrate | we will/shall concentrate |
| 2 | you will/shall concentrate | you will/shall concentrate |
| 3 | he/she/it will/shall concentrate | they will/shall concentrate |
| conditional simple | | |
| 1 | I would concentrate | we would concentrate |
| 2 | you would concentrate | you would concentrate |
| 3 | he/she/it would concentrate | they would concentrate |
| present continuous | | |
| 1 | I am concentrating | we are concentrating |
| 2 | you are concentrating | you are concentrating |
| 3 | he/she/it is concentrating | they are concentrating |
| past continuous | | |
| 1 | I was concentrating | we were concentrating |
| 2 | you were concentrating | you were concentrating |
| 3 | he/she/it was concentrating | they were concentrating |
| future continuous | | |
| 1 | I will be concentrating | we will be concentrating |
| 2 | you will be concentrating | you will be concentrating |
| 3 | he/she/it will be concentrating | they will be concentrating |
| conditional continuous | | |
| 1 | I would be concentrating | we would be concentrating |
| 2 | you would be concentrating | you would be concentrating |
| 3 | he/she/it would be concentrating | they would be concentrating |
| present perfect | | |
| 1 | I have concentrated | we have concentrated |
| 2 | you have concentrated | you have concentrated |
| 3 | he/she/it has concentrated | they have concentrated |
| past perfect | | |
| 1 | I had concentrated | we had concentrated |
| 2 | you had concentrated | you had concentrated |
| 3 | he/she/it had concentrated | they had concentrated |
| future perfect | | |
| 1 | I will have concentrated | we will have concentrated |
| 2 | you will have concentrated | you will have concentrated |
| 3 | he/she/it will have concentrated | they will have concentrated |
| conditional perfect | | |
| 1 | I would have concentrated | we would have concentrated |
| 2 | you would have concentrated | you would have concentrated |
| 3 | he/she/it would have concentrated | they would have concentrated |
