i liked you 是我以前喜欢你,但不一定表示现在不喜欢.
是否现在不喜欢要看语境和上下文.
如果现在不喜欢,比较准确(并无歧义)的表达是
I have liked you
I did like you
而且,说者有时会补充 but/though 什么什么,比如
I have liked you,but things are different now.
I did like you,but things changed.
Though I no longer feel this way,I did like you.
等等.