`1.` She asked me What I had joined the environmental event.

`@` Câu tường thuật với Wh_question:
S + asked + sb + Wh_ + S + V( lùi thì)

`-` lùi thì :QKĐ `->` QKHT

`2.` Same said she had read climate change two days before.

`@` Câu tường thuật : (+)

S + said + (that) + S + V(lùi thì)

`-` lùi thì : QKĐ `->` QKHT

`3.` I asked the speaker How technology affected environment.

`@` Câu tường thuật với Wh_question:
S + asked + sb + Wh_ + S + V( lùi thì)

`-` lùi thì: HTĐ `->` QKĐ

`4.` My sister said that she was going to the conference on plastic the next week.

`@` Câu tường thuật : (+)

S + said + (that) + S + V(lùi thì)

`-` lùi thì : HTTD `->` QKTD

`-` next week `->` the next week 

`1`. She asked me what I had joined the environmental event.

`-` Lùi thì: QKĐ `->` QKHT

`-` Đổi ngôi: You `->` I

`2`. Jame said that he had read about climate change two days before.

`-` Lùi thì: QKĐ (read) `->` QKHT (had read)

`3`. I asked the speaker how technology affected the enironement.

`-` Lùi thì: HTĐ (affect) `->` QKĐ (affected)

`4`. My sister said that she was going to the forence on plastic pollution the following week.

`-` Lùi thì: am going to `->` was going to

`-` Next week `->` The following week.

`--------`

`@` Câu tường thuật Wh-questions:

`-` S + asked/wondered/wanted to know + (O) + wh-word + S + V(lùi thì)

`@` Câu trần thuật ~ gián tiếp:

`-` S + said/told/said to + (O) + (that) + S + V(lùi thì)