One swallow does not make a summer.

一燕不成夏。

《新英汉大辞典》

One flower does not make a spring; one swallow does not make a summer.

鲜花一朵还不是春天，孤燕一只不成夏天。

youdao

One swallow does not make a summer. — John Taverner, English composer and organist.

一燕不成夏- - -约翰。泰维纳，英国作曲家和风琴演奏家。

youdao

"For the high street, one swallow does not make a summer, but these results might hint at the green shoots of recovery, or at least some stabilisation in the current environment, " Ms Wehrle added.

BBC: Shopper

One swallow does not a summer make, of course.

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