The phrase "by now" is commonly used to indicate that something should have happened or be known at this point. However, there are several synonyms that can be used interchangeably with this phrase. "Already" can suggest early completion or the passing of time, while "thus far" emphasizes the length of time that has elapsed. "Up to this point" is another option, highlighting the current state of affairs. "Until this moment" is used to imply that something has occurred at a specific point in time, while "so far" suggests something is still ongoing. Ultimately, these synonyms provide a level of flexibility when describing past events or current situations.