此情可待成追忆，只是当时已惘然 翻译成英文

此情可待成追忆，只是当时已惘然 翻译成英文

以下是许渊冲所译的 锦瑟( The Inlaid Harp)全诗，你的这两句是最后两句。

锦瑟无端五十弦 I wonder why my inlaid harp has fifty strings,
一弦一柱思华年 Each with its flower-like fret an interval of youth.
庄生晓梦迷蝴蝶 ...The sage Chuangzi is day-dreaming, bewitched by butterflies,
望帝春心托杜鹃 The spring-heart of Emperor Wang is crying in a cuckoo,
沧海月明珠有泪 Mermen weep their pearly tears down a moon-green sea,
蓝田日暖玉生烟 Blue fields are breathing their jade to the sun....
此情可待成追忆 And a moment that ought to have lasted for ever
只是当时已惘然 Has come and gone before I knew.

此情可待成追忆，只是当时已惘然。 This feeling can be treated into the palimnesis, just already dejected at that time.