When we want to express that something happened suddenly or quickly, we often use the phrase "in a twinkling." However, if we want to vary our language and use more descriptive words, we can consider synonyms such as "instantaneously," "swiftly," "speedily," "promptly," or "immediately." These words convey a sense of urgency or immediacy, and can be used in different contexts, such as describing a sudden change in attitude, a quick decision, or a swift movement. Experimenting with different synonyms can also add variety and depth to our writing, making it more engaging and expressive.