Being new to Chinese please forgive any ignorance of mine.
In lesson 2.2, line 2, the sentence structure is "nin yao mai...ma?". In lesson 2.3, line 5, the sentence structure is "ni yao mai...?" Is it optional to use "ma" to form a question with this sentence structure? There doesn't seem to be any question words (e.g. ji , shenme) in either of these sentences so I would think both would need "ma" at the end to be question sentences.
Appreciate any clarification. Thanks.