He has been watching English movies since about two month 這句

題目：

He has been watching English movies since about two month 這句話有錯嗎?

解答：

有,應該改爲「He has been watching English movies since two month ago".
再問： 那 since about two months 對 還是for zbout two months 對
再答： for zbout two months對。 因爲只有for加一段時間, 如果有since的時候，」since about two months「就要加ago.