I must admit that I can't figure out when to use or not use "the" in front of the noun. I'm certain that there are rules that I just don't know or remember, but it seems every time I omit the article it is wrong and when I include it it's also wrong :-(
It depends on the formulation; it could be "loro sono idraulici" or "loro fanno gli idraulici".
It's still confusing for me. Loro sono gli idraulici means they are THE plumbers, I see, but can that mean they are plumbers?
If the sentence has a "the" article, you are supposed to use "the" in the translation. A time where you would not use "the" is when you have the article "degli/della/del/dello" because "di" can be used as a possessive, but can also be used to mean "some" or an unmentioned quantity. i.e. "Degli uomini parlano al ragazzo." can mean "Men speak to the boy." with an unspecified and unquantified number of men, or it can mean "Some men speak to the boy." with an quantified amount of men, though it has specified that there is a limited amount of men. How it is translated is personal taste and the differences are only semantics, but the bottom line is that if you see "gli" you write the translation with "the" and if you see "degli" then as long as it is not being used as a possessive, then it is safe to leave it out of the translation.
This is how I understand it, if I am wrong, please correct me.
Do you mean specifically when it comes to occupations?
There are many instances where Italian requires an article but English does not.
Occupations, however, seems has some special rules that I don't understand.
A similar sentence about my parents being lawyers used degli avvocati and the translation did not use "the."
The phase is confusing because plural "the" normally requires a defining clause ("they are students" vs "they are the students we saw yesterday") or a unique set ("they are brothers" vs "they are the Mario brothers").
The inconsistent use of articles really bothers me. Sometimes they are deemed absolutely necessary, even if the answer sounds a little odd. Other times you can just skip them. Please Duolingo, make it consistent. Either you have to use the article all the time or you don't.
Im sure that this was explained on the computer version, but I've never been clear what makes and masculine plural use gli instead of i... Can anyone help explain that for me?
That is correct. Gli is used in plural cases with masculine nouns that take lo or l' in singular case.
Why is not gl'idraulici? When do I use gl'?
I know when I have to use the normal gli, but I thought that using gli before a word beginning with letter I, it becomes gl'. Am I wrong?
As far as I know, gli is never contracted to gl' (I am not a native speaker of Italian but I've studied it for many years and never come across gl')
I thought that when reference is made to professions, the article "the" (gli) is used where it would not be used in English. Is this not the case?
I put 'they are the hydraulics' which according to the drop-down, is also right. Why did it mark me wrong??
Why does the drop down list include hydraulics, but when I use hydraulics it is marked wrong?