- The children played happily yesterday.
- Yesterday played the children happily.
- The children played yesterday happily.
- Happily played the children yesterday.
The correct sentence structure in English is Time-Subject-Adverb-Verb. The time (yesterday) should come first, followed by the subject (the children), the adverb (happily), and finally, the verb (played). The correct option (a) follows this structure.
