Questions & Answers about Телефон там? Нет, там сумка.
Why is there no word for "is" in Телефон там?
In Russian, the present tense of the verb "to be" (am, is, are) is almost always skipped. You just put the words next to each other, so the literal translation is simply "Phone there?".
How do we know Телефон там? is a question if it doesn't use a question word?
For yes/no questions, Russian doesn't change the word order or add helper words like "do" or "is" like English does. In writing, the question mark is your only clue. In spoken Russian, you show it is a question by sharply raising your voice's pitch on the word you are asking about.
If I wanted to ask "What is there?" instead, how would I use this lesson's question words?
Since a phone and a bag are inanimate objects, you would use the question word что (what). The question would simply be Что там? (What is there?). If you were asking about a person or animal, you would use кто (who).
Why does the reply say там сумка instead of сумка там?
Russian word order is very flexible, but there is a rule of thumb: the most important or newest information usually goes at the very end of the sentence. Since the speaker is correcting the first person and revealing that the object is actually a bag, сумка (bag) is the most important new information and goes last.