"Sugar is sweet."
Translation:Gula itu manis.
Not sure if my explanation is correct or not, since I speak Malay and not Indonesian, but:
I. ada - have/has/had:
Dia ada gula-gula: He/She has sweets.
II. adalah - is/are (adjectives and prepositions):
Buku itu (adalah) tebal: That book is thick.
Baju itu adalah dari Eropah: That shirt is from Europe.
III. ialah - is/are (nouns and verbs):
Dia ialah seorang murid: He/She is a student.
Usually, you can omit ialah/adalah in some cases, such as:
Buku itu tebal: That book (is) thick.
Gula itu manis: Sugar (is) sweet.
Nama saya (X): My name (is) (X).
In more advanced Malay (not sure about Indonesian), ialah, ada, and adalah are used less commonly and other words are used instead.
It's more like "a correct translation", since the preferred translation (given above) is "Gula adalah manis". (Basically, duo makes questions out of any correct solution, not just the main one.)
As to your actual question, I don't know why "itu" is included, but Google Translate akso renders "Sugar is sweet" as "Gula itu manis", so I don't think it's an error.
I also read the lesson notes up to this point and don't see any explanation of why "itu" is used thusly. It may be that, since the question comes from an /accepted/ answer rather than the /preferred/ answer, we just haven't learned that yet.
Yes, /Gula itu manis/ can mean "That/The sugar is sweet."
However, my guess is that adding /itu/ after a subject noun is also a means of distinguishing a subject of the sentence from the predicate of the aforementioned sentence. This method helps the statement look more like a complete sentence to an Indonesian. It just feels more natural.
Hello guys, I try to help.
"Adalah" can be used to explain what something is. Commonly it's a translation of "to be" that followed by nouns. E.g. I am a teacher = Saya adalah guru. You are a boy = Kamu adalah anak laki-laki. We are souls = Kita adalah jiwa-jiwa.
When "to be" followed by "adjective", commonly "to be" translated to "itu" ("that" in english, if the thing is far from the speaker or the second person), or to "ini" ("this" in english, if the speaker or the second person is close to the object). E.g. Cat is black = Kucing itu hitam Sugar is sweet = Gula itu manis Boy is cute = Anak laki-laki ini imut.
But sometimes you just don't need to add either "adalah" or "itu/ini" e.g. We are happy = Kami bahagia. You are beautifu = Kamu cantik. I am single = Saya jomblo.
I hope this explanation helps a bit