1John said to Mary " She is ready to go with us"

→ John said to Mary she was ready to go with them.

2. she said to me"they do not know you"

→ She said to me they didn't know me

3. He said "I shall answer the phone"

→ He said he would answer the phone.

4.she said to them " you can do it if you try"

→ She said to them they could do it if they tried.

5. he said "he has done his homework well"

→ He said he had done his homework well.