On 「夢だけど、夢じゃなかった」 from 「となりのトトロ」

Question

In 「となりのトトロ」, the two heroines (kind of) had a dream in which, with the help from Totoro, they made the seeds they had just put in the ground grow into a big tree.

Having woken up, they found there was no tree in the field but the seeds did sprout. Then they started to exclaim: 「夢だけど、夢じゃなかった」.

メイ「木がない…」

サツキ「あっ！」

メイ「あっ！」

サツキ「やったー！」

サツキ・メイ「わあああ…」

サツキ「夢だけど…」

メイ「夢じゃなかった。」

サツキ「夢だけど…」

メイ「夢じゃなかった。」

サツキ・メイ「バンザーイ。やったー。うふふ…　わはは…」

I wonder why they had not chosen to say 「夢だったけど」 instead of 「夢だけど」 (since the dream had ended).

Answer 1

Translating into English might make it confusing in this case.

だ in だけど is 助動詞 and used when concluding something, presenting something, or specifying something, etc. But this Japanese word だ itself actually doesn’t specify the tense, so it can be used in the past, present or future tense. Generally, the context or the other words in the sentence tell what kind of tense the sentence expresses.

So, the literal translation of their lines would be:

夢だけど… ＝ Definitely a dream, but…

夢じゃなかった。 ＝ It wasn’t a dream.

If you’d like to see the definitions of this kind of だ, here is the link.

だ（助動）in 大辞林