“Such” and “so” both mean “very”. However, the difference is that “such” is a determiner while “so” is an adverb. Therefore, they are used differently in sentences.
Since “such” is a determiner, it should be used with a noun phrase.
I am such a klutz, I forgot to bring my bus pass again!
When “such” describes the noun phrase “a klutz”, it means that I am very much a klutz (someone who behaves clumsily).
The woman has such a beautiful singing voice. It is music to my ears.
Here “such” describes just how beautiful the speaker thinks of the woman’s singing voice.
Conversely, “so” is an adverb, and is used with an adjective or an adverb phrase.
If we use “so” in the same sentences, they will now look like:
I am so klutzy, I forgot to bring my bus pass again!
Here the noun phrase “a klutz” is replaced with the adjective “klutzy”.
The woman has a voice that sings so beautifully. It is music to my ears.
Author: Katy Lia, Cambly Tutor
If you’d like to keep this conversation going with Katy, give her a call on Cambly or make a reservation with her here: https://www.cambly.com/en/student/tutor/Katy%20Lia