Sindarin song

When the moon is hidden the stars shine. Ir gives a reason to sing. When light is absent there's hope. Given by the one to the elves.(Or something like that, whatever can rhyme in sindarin)

Ir ithil torn elin calar. Sen anna nîdh allinna. Ir calad bannen dha estel.

This is a song I'm writing in sindarin, does anybody have a suggestion for the last line, and also correct mistakes?

Mae govannen Dared Ellodin!

So, let's start with your first sentence.

• “When the moon is hidden, the stars shine.”
• Io dholen ithil, i·ñgîl gelir. (When hidden [is the] moon, the stars shine.)

1. A few things with your ir its validity is also questionable, seeing as its Q. equivalent íre was replaced by yá.
2. There is no Sindarin word torn not that I can find. I would just use dolen
3. We can use elin "stars" but it seems to be updated to gil. gil has varying etymologies, and its singular form is variously attested as gil or gail. The plural gîl likely corresponds to gail, and would be regular (cf. cair > cîr). However, if you use gil as singular, it should remain unchanged in plural.
4. The conjugation for cal- present tense would be celir.

Sentence two:

• “Ir gives a reason to sing.” I think there was a typo and was meant to mean “it”.
• Se anna gaeth al linnad. (This gives [a] reason for singing.)

1. sen → se (Independent Pronoun)
2. I don't think nîdh² n. “full vigorous purpose, exertion of will” works here. I would use caeth
3. allinna → al linnad you need the infinitive hear.

Sentence three:

• “When light is absent there's hope.”
• Estel dha io ‘wanwen galad (Hope there is when gone [is] light)

1. Not a fan of da but it is the only thing we have. LOL
2. ᴺS. !bannen adj. “gone” seems to be replaced with S. gwanwen “departed, *gone, lost [to time], past”

Sentence four:

• “Given by the one to the elves.”
• Annen vo Eru enin Edhil. (Given by agent of Eru to the Elves.)

Not sure if that helps, lol But this is what I saw. I am not the best with songs.

Thank you celebrinor! This is great. (How would you say thank you in sindarin?) This can work very well as a song.

Annon allen! (I give thanks to you (polite)).