jinanbeon ilgdeon chaegi jaemiissgo gamdongjeogieosseo.

-던 is the attributive past-progressive ending. It shows that the action was ongoing at a past time.

• 읽던 책: “the book I was reading” (ongoing in the past)
• 읽는 책: “the book I am reading” (ongoing now)
• 읽은 책: “the book I read” (completed action)

Both are acceptable.

• 지난번 읽던 책: more colloquial; 지난번 directly functions as “last time.”
• 지난번에 읽던 책: slightly more explicit; -에 marks the time point “at the last time.”
  The nuance is minimal; Koreans often drop -에 in casual speech.

-고 simply links two predicates (“and”). With descriptive verbs (adjectives) in Korean, you use the dictionary stem plus -고 regardless of tense, and then apply the tense ending only on the final predicate.
Hence:

• 재미있고 (stem 재미있다
  • -고)
• 감동적이었어 (past tense on the second adjective)

감동적 is a noun-like adjective (nominal). To make it a predicate, you attach the copula -이다, which in past informal becomes -이었어.

• 감동적이야: present informal (“is touching”)
• 감동적이었어: past informal (“was touching”)
• 감동적였어 is less common because after a consonant stem we usually write 이었어.

Although grammatically possible, it sounds redundant. Native speakers normally mark tense only on the final clause when using -고:

• Natural: 재미있고 감동적이었어
• Less natural/redundant: 재미있었고 감동적이었어

This uses the informal low style (반말). To make it polite (존댓말), you would say:

• 지난번 읽던 책이 재미있고 감동적이었어요.