The past tense of ‘shake’ is ‘shook.’
This means that if you are referring to an action that happened in the past, you would use ‘shook’ instead of ‘shake.’ For instance, if you want to say that you moved something back and forth at a previous time, you would say, ‘I shook the tree to get the fruit down.’ Understanding verb forms is important in English because it helps convey the timing of actions clearly.