Reported statements often backshift after a past reporting verb: I am worried → She said she was worried. Change pronouns and time references when the reporting situation changes. Reported questions use statement word order: Where do they live? → He asked where they lived. Yes/no questions use if or whether. Do not add do/does/did inside the reported clause. A still-true fact may retain its tense when context justifies it.
Topic preview: To protect the wetland, I would combine habitat restoration, less unnecessary lighting and better waste collection. A clean-up alone cannot replace lost reeds. An expert should advise which native plants are suitable. Monthly observations from the same public path could show trends, although they would not prove a single cause.