Коротко: при переносе прямой речи в косвенную обычно происходит «сдвиг» времен назад (backshift), если вводящий глагол стоит в прошедшем времени. Также меняются модальные глаголы, порядок слов в вопросах и указатели времени/места. Привожу основные преобразования и замечания.
Основные сдвиги времён (при вводящем глаголе в прош. времени):
- $1$ Present Simple → Past Simple: "I work" → (he said) he worked.
- $2$ Present Continuous → Past Continuous: "I am working" → he was working.
- $3$ Present Perfect → Past Perfect: "I have worked" → he had worked.
- $4$ Present Perfect Continuous → Past Perfect Continuous: "I have been working" → he had been working.
- $5$ Past Simple → Past Perfect: "I worked" → he had worked.
- $6$ Past Continuous → Past Perfect Continuous: "I was working" → he had been working.
- $7$ Past Perfect → Past Perfect (без изменения).
Модальные глаголы и модальности:
- $8$ will → would.
- $9$ can → could.
- $10$ may → might.
- $11$ must → had to (часто), но must можно не менять при логическом выводе: "He must be right" → she said he must be right.
- $12$ shall → should.
Вопросы и повелительные предложения:
- Да/нет-вопросы: вводится if/whether, порядок слов обычный (подлежащее + сказуемое): "Do you like it?" → He asked if I liked it.
- Wh‑вопросы: сохраняется вопросительное слово, далее обычный порядок слов: "Where did you go?" → She asked where I had gone.
- Повелительное наклонение: глагол в инфинитиве с to после сказуемого типа asked/told/ordered: "Close the door!" → He told me to close the door.
Указатели времени и места (частые замены):
- today → that day; tomorrow → the next day / the following day; yesterday → the day before / the previous day; now → then; here → there; this → that; last week → the week before / the previous week; next week → the week after / the following week; ago → before.
Исключения и замечания:
- Если вводящий глагол в настоящем/будущем времени (например, says, is saying), или сообщение выражает общеизвестный факт/истину, сдвиг времён обычно не делается: She says, "I live here" → She says (that) she lives here.
- Если содержание сказанного по‑прежнему истинно, сдвиг можно опустить: "He said, 'I'm happy now'" → He said he is/was happy now (оба варианта возможны; предпочтителен was при строгом следовании правилу).
- В косвенной речи часто опускают вводное that: He said (that) he was tired.
Несколько примеров:
- Direct: "I will come tomorrow," she said.
Indirect: She said (that) she would come the next day.
- Direct: "Do you want coffee?" he asked.
Indirect: He asked if I wanted coffee.
- Direct: "I've finished the work," she said.
Indirect: She said (that) she had finished the work.
Это основные правила — при необходимости могу разобрать конкретные примеры.