Quomodo dicere "They left to eat ice cream"

Salvete amici amicaeque!

Valeo si valent.

Quomodo dicere “They left to eat ice cream?”

Scribo sic sententia mea:

“Discesserunt gelati edendi causa.” (GERUNDIVE, anglice)

vel:

“Discesserunt ut gelatum ederent.”

Gratias vobis ago!

Valete

Both are good, I believe, Quis ut Deus: your genitive gerundive with “causâ” or the one using the “ut” clause.
Uter modus, Quis ut Deus, bonus est, ut credo: iste per formulam cum gerundivo casu genetivo vel iste cum ut conjunctione.

Salve Adriane!

Multas Gratias tibi ago!

You can also use the gerundive with “ad” (here I’m guessing the word is “gelātum”):
Discessērunt ad gelāta edenda.

And since this is a motion verb, you can even use the supine:
Discessērunt ēsum gelāta.

While the gerundive with “causā” is surely a valid construction, I’m not sure it is the best one. I understand “[gen. noun] + causā” to basically mean “for the sake of [noun]”, and saying “They left for the sake of ice cream” sounds a bit odd. Wheelock doesn’t use this construction where “for the sake of” would be awkward in English. Of course, that doesn’t mean that the Romans didn’t…

Where did you find the Latin word for ice cream, BTW? Or did you model it on Italian “gelato”?

@furrykef-Thanks for the input!

Yeah, I started with “helado” in Spanish, and then went with “gelatus” in Latin.

Traupman (Conversational Latin for Oral Proficiency) gives “gelidum crēmum” for icecream.
In Morgan, these (including your “gelatum”):

Pro anglicè “icecream” apud Traupman “gelidum crēmum” habes. Apud Morgan haec citata (quae gelatum tuum includunt).

Don’t say that in English, then. Say “for the purpose of eating” or “to eat”. See A&G §504b.
Sic anglicè non dicas sed aliter. Vide A&G sectionem quingentesimam quartam partem b.