In current Duolingo Section 4 Unit 51 (a few weeks ago was Section 3 Unit 64) Discuss Gaelic Organizations --- I have gotten this sentence a few times:
"Fèisean nan Gàidheal is an exceptional project!"
Fèisean nan Gàidheal is a proper noun whose spelling has not varied in the sentences I've had so far. Also Fèisean nan Gàidheal doesn't seem to have an article attached to the front that would indicate what grammar pattern to use. For example, like cities whose Gaelic names may or may not have an article, such as, Glasgow versus Oban (an t-Oban).
fèis is a feminine noun and in a dative case might be written as "ann an fhèis". ("in a festival") Nominative case definite form would be "an fhèis" (the festival).
BUT "ann an" is a preposition followed by the dative/prepositional case where it usually becomes "ann am" before an indefinite noun starting with b, f, m, p.
Here is my question: What is the correct Gaelic translation for "Fèisean nan Gàidheal is an exceptional project!"?
A few days ago 'S e pròiseact air leth a th' ann am Fèisean nan Gàidheal! was correct. Note the use of "am."
Today, the system generated this "'S e pròiseact air leth a th' ann an Fèisean nan Gàidheal!" and asked for the English translation. Note the use of "an" and no lenition on "Fèisean."
Translating back to English is easy enough. But if I have to type the Gaelic, this an/am question could "cost" me a heart and the free version of Duo only allows 5 hearts per day. Also, I'd really like to know what the correct grammar is in this case. My first guess would be "ann am" following the grammar for the preposition because the noun in this case is a proper noun which seems to have standard spelling. But, then again, I could easily be wrong.
This is a new topic that doesn't have any grammar notes on the duome page and Duo's guidebook sentences don't provide any clues.
Any ideas?
Thank you.
26August2025 edit -- found this item below online at the link, using "Fèisean nan Gàidheal" in a sentence.
https://www.highland.gov.uk/site/gaelic ... index.html
Fèisean nan Gàidheal
'S e buidheann neo-eisimeileach a th' ann am Fèisean nan Gàidheal agus tha grunn fhèisean teagaisg Gàidhlig fo sgèith na buidhne seo. Tha Fèisean nan Gàidheal a' toirt seachad tabhartasan is prògraman trèanaidh, agus tha iad an sàs ann an tòrr iomairtean eile a tha a' brosnachadh na Gàidhlig agus a cultar.
Fèisean nan Gàidheal is an independent umbrella organisation for many of the Gaelic teaching festivals in Scotland. Fèisean nan Gàidheal gives support funding and delivers training programmes, and they are involved in many initiatives which promote the Gaelic language and its culture. <www.feisean.org>
So " 'S e buidheann neo-eisimeileach a th' ann am Fèisean nan Gàidheal " uses "am" - but then the question remains why would Duolingo use "an Fèisean nan Gàidheal" in their sentence?
Thanks again for any ideas.

