I can only imagine: to form or have a mental picture or idea of something or someone; If you imagine something that is not real or true, you think that it exists, has happened, or is true. I can only imagine means you can’t really be in the scene. You just have to imagine it.
As in I can only imagine how he must have felt, entering the Oval Office in turbulent times.
中文释义：I can only imagine，我只能想象；超出我的判断；超乎寻常。适用于以下两种场景：1、对说话方所提及的某种状态的理解和共鸣，表达自己设身处地、感同身受的一种认可；2、对于说话方所描述的某件事情感到惊讶，或认为它超出了真实环境下能够被人所接受的范围，比如，好的令人憧憬和向往，坏的令人难以面对。只能通过想象来模拟当时的情境。例句：I can only imagine how he must have felt, entering the Oval Office in turbulent times.（我只能想象他在那个动荡的年代步入椭圆形办公室时的所思所想。）