How do you spell knew in spanish?

The Spanish word for "knew" depends on the tense. There isn't one single translation. You need to consider the context.

* If it's the simple past tense: The most common translation would be supe (for "I knew"), or the appropriate conjugation of the verb saber (to know) for other subjects (e.g., supo, supimos, supisteis, etc.).

* If it's a perfect tense (having known): You might use the present perfect with haber + sabido (e.g., he sabido, has sabido, etc.).

* If it refers to past knowledge in a more general sense: You might use sabía (I knew, I used to know), a past imperfect tense.

To give you the correct translation, please provide the sentence containing "knew".