What context can I use each word in?
Learn when and how to use these words with these examples!
unfasten
Example
Can you please unfasten my seatbelt? [unfasten: verb]
Example
She unfastened her necklace and put it in the jewelry box. [unfastened: past tense]
undo
Example
I need to undo this knot before I can use the rope. [undo: verb]
Example
He had to undo all his hard work when he realized he made a mistake. [undo: past tense]
Good things to know
Which word is more common?
Undo is more commonly used than unfasten in everyday language. Undo is versatile and covers a wide range of contexts, while unfasten is less common and typically used in the context of physical objects.
What’s the difference in the tone of formality between unfasten and undo?
Both unfasten and undo are neutral in formality and can be used in both formal and informal contexts.
