“留念”这个词的英文怎么拼写

留念可译为 as a memento （变体拼写 momento）, as a souvenir, as a keepsake
最佳翻译要看语境， 比如
合影留念 have a group photo taken to mark the occasion;
照相留念 have a photo taken as a memento;
赠物留念 to give a present as a keepsake.

不同的语境可以有不同的说法用法
比如接受礼物作为留念
你可以说
accept/keep it (as a souvenir作为纪念):
合影留念have a group photo taken to (mark the occasion留念v);
照相留念have a photo taken （as a memento作为纪念）;

部分忘记拍照留念翻译

accept(keep) as a souvenir