"Experiments are done in the laboratory."

Translation: Déantar turgnaimh sa tsaotharlann.

[PatHargan]

Should there be a 't' before 'saotharlann' or not? Both are given as the 'correct solution'.

[galaxyrocker]

The would t only come in (I believe) Connacht Irish, where sa eclipses and prefixes feminine nouns that start with s with a t

[PatHargan]

Thanks. I decided to look it up after reading your response. Apparently, 'sa lenites consonants b, c, g, m, p, and prefixes t to initial s of feminine noun; san lenites' (http://www.teanglann.ie/en/fgb/i).

[galaxyrocker]

Note that that is only in the standard, and not all dialects lenite or prefix the t to feminine nouns. Gramadach na Gaeilge is much better than teanglann in regards to showing how grammar actually varies across dialects.

http://www.nualeargais.ie/gnag/i.htm

[PatHargan]

Thanks for the tip!

[scilling]

Even the teanglann.ie description isn’t a complete answer; a T would only be prefixed to a feminine noun that begins with S followed by either L, N, R, or a vowel (for instance, one wouldn’t use sa tscuab).

[AinePoilin]

The correct answer is listed as either 'sa saotharlann' or 'sa tsaotharlann' -- why doesn't "sa(n)" trigger lenition here?

[gruamaire]

is ts pronounced like ts or just t

[scilling]

For the ts in tsaotharlann, only the t is pronounced.

[clairelanc3]

Why in a previous sentence does Duo reject experiments are DONE and wants MADE?

[19O492554]

I'm pretty sure that Duolingo didn't reject "experiments are done" in favour of "experiments are made".

Déan is used to translate both "do" and "make", but the most appropriate translation depends on the English idiom:
Déan do dhícheall - "Do your best"
Tá na páistí ag déanamh glór - "The children are making noise"
Sometimes it doesn't matter whether you use "do" or "make", but in these examples it does.