未必总是的英文：
not always

Concessions are not always purely negative in character.
就其特性而言，让步未必总是纯粹消极的。

always; forever
老是

I have always pitied the delusion, always.
我对于受欺骗者总是有怜惜之心的。

In that spot the night was not always empty, the darkness not always silent.
在那个地点，夜色里并不老是空无一人，黑暗里也并不老是鸦雀无声。

Roosevelt, on the other hand, was always charming, always the aristocrat
另一方面，罗斯福总是那么有吸引力，又总是保持一副贵族的派头。

Has he always been a vegetarian?
他总是吃素吗？