The phrase "what did they" is an incomplete question commonly used in English to inquire about actions performed by a group or unspecified individuals.
Grammatically, it begins a past-tense interrogative sentence. To complete it, you typically add a verb or context—for example:
- What did they say?
- What did they do yesterday?
- What did they think about the proposal?
This construction follows standard English question formation for past simple tense with "do"-support: What + did + subject + base verb?
Understanding such phrases helps learners grasp how questions are formed and interpreted in real-world conversations.