I can't answer your question directly, but I can point you to a site which conjugates every French verb in every form and tense:

https://www.verbix.com/webverbix/go.php?&D1=3&T1=ralentir

@Chris So, I'm not sure what you think I was asking, but my question was actually regarding this: Kwiziq gave us a lesson in how to conjugate "-tir" verbs, as is linked above. The lesson did not say anything about exceptions. Then, in a quiz, we are tested on "ralentir," which does NOT follow the rules outlined in the lesson, because it is just a regular "-ir" verb, and the quiz question is linked to "how to conjugate '-ir' verbs". So if we are paying attention to what we are taught, and conjugate "ralentir" in the quiz--as we were taught for "-tir" verbs--then we get the question wrong. There is literally no way to know we are being tricked and that "ralentir" is an exception to the "-tir" rules. The only way you could get it right is to not have paid attention to the "-tir" lesson, and the question should be removed AND the "-tir" lesson clarified as to when these rules are needed.

@Cecile--I appreciate your trying to help, but it is a little frustrating that your answers to my queries never answer the question I actually asked, yet are somehow marked instantly as the correct answer. If you will read the two items I wrote, they actually mention that "ralentir" is used in a KWIZ--not in the above lesson. My point is that everything in the linked "-tir" lesson would lead you to believe that ralentir should be conjugated thusly. If there are exceptions (such as "ralentir"), that should be mentioned. If the "-tir" verbs mentioned are themselves the exceptions, and regular verbs like "ralentir" outnumber them, THAT should be mentioned. My point, once more, is that we should not be taught that "-tir" verbs get a special conjugation, and then get kwizzed on a "-tir" verb that does not get it, without further clarification. And yet that is indeed what is happening. I hope this all makes sense to you now. Thanks.

I can't imagine what difference that would make, since the issue is not with the question itself, as the question and answer is not in itself incorrect (https://progress.lawlessfrench.com/my-languages/french/tests/results/14363418/system), and none of my posts have indicated otherwise. The issue, one final time, even though I have said this repeatedly now, is that we are taught in the lesson--which again, to be clear, does not mention "ralentir"--that "-tir" verbs are conjugated a special way. ONE exception to this apparent rule is mentioned--and it is not ralentir. So then to test us on a kwiz--even if the answer is correct--on "ralentir," which does not follow the "-tir" pattern, is to force us to get the answer wrong if we follow the incomplete information we were given in the lesson. The question should therefore be removed, or the lesson clarified (which obviously should happen anyway, since it is misleading, making it appear that there is only perhaps one exception to the irregularity), or both. Please truly consider having a colleague look over what I am saying; I really don't have it in me to say it all again. Thank you.

Thanks, but putting information somewhere else still doesn't help anyone who is reading the "-tir" lesson and comes away with the very understandable impression that most, if not nearly all, "-tir" verbs follow the irregular pattern. All that needs to be done to fix the whole problem is change the ambiguity of the lesson by writing something like: 

"Some/most -tir verbs follow an irregular pattern"... 

"The following verbs are some/most of the verbs that follow this irregular exception." 

In other words, you guys need to make it clear that not all "-tir" verbs are irregular, and that the one regular-conjugation verb that you list as an exception is not an isolated case, but that there are in fact many more. This is the issue, and the fix. (And I know ralentir is regular--if it wasn't, none of this would have made any sense. Was never asking for it to be put in the lesson.)

Here is what the lesson currently states: "The verb partir (to leave), as other -TIR verbs* ["other irregular verbs" are linked here by the asterik, which does nothing to clarify the ambiguity], is irregular in Le Présent." How am I not supposed to think ralentir would also be included with a statement like that? "Some other" or "most other" is called for. I can not make it any plainer than that.

Finally, you already have a quiz question that involves conjugating ralentir as a regular verb. That is what prompted this post, as I have repeatedly said. At this point I am desperately requesting that you have a colleague actually read what I am writing, rather than pass along your summary. Please. I have written what the issue is over and over again.