what is ...말만 잘 할거라고 생각해? translated to English?
...말만 잘 할거라고 생각해?

I know each word individually but i can't seem to figure out the sentence structure in English to make it, make sense.
To give an idea of what's going on, if it helps, these were said beforehand...

Person A: 너무 기뻐서 가슴이 터져버릴 것 같으니까.
Person B: 말은 잘 하네
Person A: ...말만 잘 할거라고 생각해?

Also what does 스윽.. i keep seeing it in manhwa as a background sound/action word and i can't tell if it's something to do with touch, sliding,pulling, or other

Question

what is ...말만 잘 할거라고 생각해? translated to English?
...말만 잘 할거라고 생각해?

I know each word individually but i can't seem to figure out the sentence structure in English to make it, make sense.
To give an idea of what's going on, if it helps, these were said beforehand...

Person A: 너무 기뻐서 가슴이 터져버릴 것 같으니까.
Person B: 말은 잘 하네
Person A: ...말만 잘 할거라고 생각해?

Also what does 스윽.. i keep seeing it in manhwa as a background sound/action word and i can't tell if  it's something to do with touch, sliding,pulling, or other

Answer

말만 잘할거라고 생각해 can translate:  I'm not just bluffing 
and about 스윽, its kind of sound effect when you reach to grab something or you move slow or gently.

Non perdere l'opportunità di imparare una lingua comodamente da casa tua. Esplora la nostra selezione di insegnanti di lingue esperti e iscriviti subito alla tua prima lezione!