"У тебя есть длинная ложка?"
Translation:Do you have a long spoon?
Forgive me for bringing up an elementary subject relatively far into the course, but at this point I feel the need to make clear: how could you distinguish, in Russian, between the questions "Do you have a long spoon" and "Do you have the long spoon", given that words like "a" and "the" have no cognate in Russian? Is it just something for which you need either context or extra words (such as "my sister's spoon") to make clear?
Intonation and word order. The exact wording will change depending on what you mean by "Do you have the large spoon?"
For example, if the exact owner/holder of the spoon is in question, "Большая ложка у тебя?" is rather typical structure.
If I understand correctly, "есть" can be omitted without changing the meaning of the sentence. When would "есть" be included and when would it be omitted? Casual talking, written in books, strangers vs. friends, etc. Are there any guidelines? Was this already covered somewhere on the site and I missed it? If so, I'm sorry.
Есть is included if the presense of the object is important, it is ommited if it is't. Without «есть» the sentence means either "Is your spoon long?" or "Is it you who has the long spoon?"
With word order or (obligatory) with intonation. Normally, if you ask who has the spoon, you or someone else, it is "Длинная ложка у тебя?" If you do not use this phrasing, then the word order will not be neutral in terms of this meaning, and will have to be supported by intonation.
Is this any perticular sort of spoon called «длинная ложка» or is this a classical random Duolingo sentence without no real meaning? I find it odd that someone would use the adjective ‘long’ with the noun ‘spoon.’
It is a random sentence on adjectives. A wide range of objects might (in theory) be large and small, long and short, light and heavy.
There are, of course, combinations that can mean more than the sum of their parts. For example, больша́я сини́ца is a great tit, and се́рая воро́на is a hooded crow (immensely more common than a black crow, at least in Moscow). Чёрная зарплата is a salary paid while avoiding taxation, "under the table" whereas белая зарплата is a fully legal salary. Guess what серая зарплата is.
Is this intonation that of a question? I can't tell the difference.