어디 그뿐인가요? 어디 is used to emphasize the speaker's feeling. 그뿐인가요? means 'it's not the only thing.' so if you say 그뿐이야, it means 'that's it.' ~ㄹ 때도 means 'even 귀를 쫑끗 세우다 is a kind of phrase, so when you pay all your attention to listen something. You can use this phrase. For example, you are talking with your boss, so you should catch every words that the boss says. In this situation you can use 귀를 쫑끗 세우다. 세우다 means 'build' or 'raise' 그림자 - shadow 만 is used to emphasize or confine the noun. 철렁 is used to emphasize the surprising situation, like only or just. 내려앉다 means 'break or fall' 철렁 내려앉다 is a sort of phrase, it means 'extremely surprised.' Therefore, 그림자만 보아도 철렁 내려앉아요. means 'I'm surprised, when I see just a shadow.' ---- 하도 means 'so often, so many times', it doesn't come from '하다' 이렇게 implies 'such a' 길어졌다고요 - '고요' is used for showing the empathy, but doesn't have an actual meaning. Or you can use '구요.' Both are the same meaning, yet it is far from a real speaking. Hence, you'd better not use '고요' in a daily conversation.