"They seem to be bad."
Translation:Ils semblent mauvais.
The whole course is written in French. Each French sentence is translated to English by contributors, with as many variants as sensibly possible, including British English ones.
Then, a "best" translation is chosen (*) and, in turn, back-translated to French variants, which will be used for reverse exercises.
When you enter a French sentence, the system compares it on a sign by sign basis with all the French translations the contributors entered in the database. If no similar sentence can be found, your translation is rejected.
The listening exercise (type what you hear) works differently: it compares your submission with the original, written French sentence only, which explains that homophones (like "il mange" vs "ils mangent") are not recognized, which generates false negatives. An algorithm allows for typos, provided that the 'typoed' word is not another French word, in which case, your translation is graded as incorrect.
(*) The "best" English translation is the one that adheres most closely to the French structure and vocabulary while still respecting English grammar rules. This is to reinforce the French sentences and to help with the reverse translations, where you translate the English sentence back into French. As a consequence, users should resist the temptation to produce their most "natural/idiomatic English" or other interpretations from the French sentences.
Sitesurf, I also assumed "être" was necessary except I used "avoir l'air". I wrote "Ils ont l'air être mauvais" but Duolingo didn't like the "être" and took it out.
So does that mean "avoir l'air" = "seems to be" so "être" is never needed because it is implied? How would you say "she seems (to be) happy"?
Avoir l'air is used without "être" in general, although you can use it:
elle a l'air d'être heureuse - elle a l'air heureuse
note a slight nuance with: elle a l'air heureux (only the "air"=appearance is happy).
elle semble (être) heureuse = elle paraît heureuse.
Note that être, paraître, sembler, devenir, demeurer and rester are "state verbs", meaning that they describe a situation or a state, so there is a lot in common among these verbs, to which we could easily add "avoir l'air".
"des maux" is indeed the plural of "un mal" - noun - meaning ill (noun), discomfort, illness, problem, issue...
- un mal de tête (headache) - des maux de tête (headhaches)
if "mal" does not have a determiner, it is either an adjective (mauvais, mauvaise, mauvais, mauvaises) after states verbs (être, sembler, paraître, devenir, rester) or an adverb after other verbs:
- they seem bad = ils semblent mauvais / elles semblent mauvaises
- this soup smells bad = cette soupe sent mauvais
"sembler" is one of these verbs that do not need a preposition to introduce another verb in infinitive.
This is the whole list: aimer/aimer mieux, aller, compter, croire, daigner, devoir, entendre, espérer, faire, falloir, (s')imaginer, laisser, oser, penser, pouvoir, prétendre, savoir, sembler, sentir, valoir mieux, venir, voir and vouloir.