| I | slacken |
| you | slacken |
| he/she/it | slackens |
| we | slacken |
| you | slacken |
| they | slacken |
| I | have slackened |
| you | have slackened |
| he/she/it | has slackened |
| we | have slackened |
| you | have slackened |
| they | have slackened |
| I | slackened |
| you | slackened |
| he/she/it | slackened |
| we | slackened |
| you | slackened |
| they | slackened |
| I | had slackened |
| you | had slackened |
| he/she/it | had slackened |
| we | had slackened |
| you | had slackened |
| they | had slackened |
| I | will slacken |
| you | will slacken |
| he/she/it | will slacken |
| we | will slacken |
| you | will slacken |
| they | will slacken |
| I | will have slackened |
| you | will have slackened |
| he/she/it | will have slackened |
| we | will have slackened |
| you | will have slackened |
| they | will have slackened |
| I | am slackening |
| you | are slackening |
| he/she/it | is slackening |
| we | are slackening |
| you | are slackening |
| they | are slackening |
| I | have been slackening |
| you | have been slackening |
| he/she/it | has been slackening |
| we | have been slackening |
| you | have been slackening |
| they | have been slackening |
| I | was slackening |
| you | were slackening |
| he/she/it | was slackening |
| we | were slackening |
| you | were slackening |
| they | were slackening |
| I | had been slackening |
| you | had been slackening |
| he/she/it | had been slackening |
| we | had been slackening |
| you | had been slackening |
| they | had been slackening |
| I | will be slackening |
| you | will be slackening |
| he/she/it | will be slackening |
| we | will be slackening |
| you | will be slackening |
| they | will be slackening |
| I | will have been slackening |
| you | will have been slackening |
| he/she/it | will have been slackening |
| we | will have been slackening |
| you | will have been slackening |
| they | will have been slackening |
| I | would slacken |
| you | would slacken |
| he/she/it | would slacken |
| we | would slacken |
| you | would slacken |
| they | would slacken |
| I | would have slackened |
| you | would have slackened |
| he/she/it | would have slackened |
| we | would have slackened |
| you | would have slackened |
| they | would have slackened |
| I | would be slackening |
| you | would be slackening |
| he/she/it | would be slackening |
| we | would be slackening |
| you | would be slackening |
| they | would be slackening |
| I | would have been slackening |
| you | would have been slackening |
| he/she/it | would have been slackening |
| we | would have been slackening |
| you | would have been slackening |
| they | would have been slackening |
| You | slacken |
| we | Let's slacken |
| You | slacken |