I have heard of dragons

[Omzinesý]

Vtain doesn't have grammatical evidentials. Kahichali does, but I'll practice with Vtain.

Kïrimba isn't an equivalent of 'dragon', but it is a flying snake from Soul world, and it is believed to be able to visit the visible world sometimes. Krimba, by the way, means a real snake.

Gle kïrimp plomäne.
kl-a kïrimb-ø plom-än-e
PRON.SG1-SPEC.DAT kïlimba-NONSPEC.INTR tell-PASS-PERF.PST
Lit: 'To me kïlimba was told.'

CPEC -specific
NONSPEC - non-specific
INTR - intransitive case

Plomi is a transitive verb (like discuss), so it must be passivized because the one who tells is not mentioned.

[Znex]

ἀκήκοα περὶ τῶν δρακοντῶν
hear-PERF-IND-ACT.1SG about DEF.M-GEN.PL dragon-M.GEN.PL
I have heard about dragons.

[Chagen]

Heocg:

Not terribly interesting. "dragons" is in the Dative and the whole sentence basically means "I have been informed of dragons":

Fah ęfragibhuh gurtyur.
1SG.NOM dragon-DAT.PL inform-PASS-PST

Note that the word I glossed as "dragon" is a Heocg folk monster called an "Ēfragū". It lives in the sea and is made completely out of paper. Every hundred years or so, it comes up and demands that someone write an epic story whose length equals the amount of paper on it. If someone succeeds, the Ēfragū grants immense riches to them and their tribe. If they fail it kills them and their tribe.

[Valosken]

Savar dragað.
sav-ar draga-ð
remember-1S dragon-PLU:ACC

Pretty boring eh.

[Sangfroidish]

Sa'ythfyre bwyhrrêgser meo.
saˈɪθfɪɾe ˈvwɪr̥ːɤɣseɻ mew
PERF-inform-3s dragon-PL.DAT.NEUT 1s.ACC
Literal: I have been informed regarding dragons

[prettydragoon]

Rireinutire

tarañono yakave:
ˈtɑɹɑˌŋono ˈjɑkɑve
dragon.NOM be-PRS-HSY
There are dragons (I have heard).

tarañono is not a mythological creature native to Rireinu, it's simply a borrowing of the Human word 'dragon'.
-ve is hearsay evidential, one of the three evidential suffixes of finite verb forms.

[thetha]

I don't have a word for dragon in my Quechua dictionary, so I'll use the word for 'snake'

Amarukuna kankus.
snake-PL be-3PL=HEARSAY

Or

Amarukunamanta uyarirqanin.
snake-PL-ABL hear-PST-1S=ASSERTIVE

The evidential on the second is asserting the fact that the information has been conveyed to me, in contrary to the first where the evidential is referring to the matter of the existence of snakes.

[Thakowsaizmu]

Nimesikia juu ya nondo
/ni.mɛ.si.'ki.ɑ ɗʒu: jɑ 'nɔ.ⁿdɔ/

ni-me-sikia juu ya nondo
1ps-PERF-hear about PART dragon(s)

[Plusquamperfekt]

...

[Bagliun Edar]

I have heard of dragons

Obulamga
Uroblemthaigrurdo igrinbroabil.
[ˈuɾɔblɛmðaiˌgɾuɾdɔ ˈigɾinbɾɔˌabil]
uroblemthai-grur-do igrin-bro-abil
dragon-PL.INDF.NEUT-TOP hear-EVID.POL-1SG.NOM

EVID: "evidentive" mood

[Xing]

Let's try a little variation:

I have heard about dragons, but they don't exist.

Or alternatively:

I've been been told about dragons, but they don't exist.

Or maybe:

People have told me about dragons, but they don't exist.

Wakeu

Ko kerakera a era mai me okarulannga, teya kuri ima.
PFV PL.tell ERG 3p 1s INSTR dragon, but NEG.exist DEM.PL

or:

Ko kerakera a era okarulannga mo mai, teya kuri ima.
PFV PL.tell ERG 3p dragon DAT 1s, but NEG.EXIST DEM.PL

[Jackk]

Chudihr
There's two kinda different ways to say this with slightly different meanings:

adŗefan iuichie asou.
adŗ-efan i-uich-i-e as-sou
hear-1s.PFV SUBD-live-IRR-3s.IMP snake-fly
I have heard that dragons exist.

sachùa iuichie asou.
sachù-a i-uich-i-e as-sou
hear-1s.IMP SUBD-live-IRR-3s.IMP snake-fly
I know that dragons exist.

Or, for a little variation:

adŗefan iuichie asou, sedi da uiches.
adŗ-efan i-uich-i-e as-sou sedi da uich-es
hear-1s.PFV SUBD-live-IRR-3s.IMP snake-fly but NEG live.NMLZ
I have heard about dragons, but they don't exist.

[Bagliun Edar]

I have heard about dragons, but they don't exist.

Obulamga
Uroblemthaigrurdo igrinbroabilzē, zoreimzē.
[ˈuɾɔblɛmðaiˌgɾuɾdɔ ˈigɾinbɾɔaˌbilzɛː, ˈzɔɾɛˌimzɛː]
uroblemthai-grur-do igrin-bro-abil-zē, zo-reim-zē
dragon-PL.INDF.NEUT-TOP hear-EVID.POL-1SG.NOM-CONJ, IND.POL.NEG-exist-CONJ

I've been been told about dragons, but they don't exist.

Obulamga
Uroblemthaigrurdo lambrōrdulabilzē, zoreimzē.
[ˈuɾɔblɛmðaiˌgɾuɾdɔ ˈlambɾɔːɾdulaˌbilzɛː, ˈzɔɾɛˌimzɛː]
uroblemthai-grur-do lam-bro-or-dul-abil-zē, zo-reim-zē
dragon-PL.INDF.NEUT-TOP say-EVID.POL-PASS-DAT-1SG.NOM-CONJ, IND.POL.NEG-exist-CONJ

People have told me about dragons, but they don't exist.

Obulamga
Uroblemthaigrurdo abamgrur lambrozē abameurodul, zoreimzē.
[ˈuɾɔblɛmðaiˌgɾuɾdɔ ˈabamgɾuɾ ˈlambɾɔzɛː ˈabamɛuˌɾɔdul, ˈzɔɾɛˌimzɛː]
uroblemthai-grur-do abam-grur lam-bro-zē abam-e-uro-dul, zo-reim-zē
dragon-PL.INDF.NEUT-TOP person-PL.INDF.NEUT-[ERG] say-EVID.POL-CONJ person-SG.DEF.MASC-this-DAT, IND.POL.NEG-exist-CONJ

EVID: "evidentive" mood.
DAT: dative case. When a case marker follows the passive voice marker, that case becomes the subject of the verb.
The "-zē" clitic conjunction is the equivalent to "but". It's attached to the verbs of the opposed clauses.

Here it is without the evidentive mood:
I know about dragons, but they don't exist.

Obulamga
Uroblemthaigrurdo bemdojoabilzē, zoreimzē.
[ˈuɾɔblɛmðaiˌgɾuɾdɔ ˈbɛmdɔʒɔaˌbilzɛː, ˈzɔɾɛˌimzɛː]
uroblemthai-grur-do bemdo-jo-abil-zē, zo-reim-zē
dragon-PL.INDF.NEUT-TOP know-IND.POL-1SG.NOM-CONJ, IND.POL.NEG-exist-CONJ

[Lao Kou]

Géarthnuns:

Sí löb chek dhbörözçöthsech bzéngöi ngköleth.
[si ˈløb tʃɛk ˌðbøɾøˈʑøθsɛtʃ bzeˈŋøj ŋˈkølɛθ]
1SG-NOM AUX.PresPRF.CAUS.PASS DEF.PL dragon-ACC.PL ever be.aware
I have heard of dragons.

[Batz]

Naguil

Eorembil robuis romunes fu.
/ɛɔ'rɛmbil 'rɔːbuis 'rɔːmunes fuː/
eo-remb-il rob-ui-s rom-un-es fu
1.SG-hear-PST verbal.exchange-ACC-PL dragon-TMP-PL near
I heard conversations around dragons.

[Znex]

Old Norse
Ek frétti til linnorma.
1SG.NOM hear_news of dragon-GEN.PL

Yorkish
Ʒ'ha hairt tal um lindormer.
/ça çeːrt tʰal ʊm ˈlɪnˌtɒrmər/
1SG.NOM have.PRS hear-PST.PART tell about dragon-PL

[lsd]

3SDL:
`´e§¥`§¶b§ªb¥G‚Þ¬©¥
(me indicated by speech about animals with breath burning...)

[Visions1]

Swang:

Xû Pɛ̇k Jaí Tʰjȧ mʘâŋ Nə̀
Heard Say-to In Wyvern PFTV
I have heard about dragons. (Formal. Implying authority of some kind.)

Xû ɲǂȉ Tʰjȧ mʘâŋ Nə̀
Hear Talk Wyvern PFTV
I've heard of dragons. (Informal. May imply people were shooting the wind. Or you're just using causal speech. "Yeah, I have.")