This is the 227th most frequent Vietnamese word.
khẳng
"Khẳng" means "thin" or "slim" (often implying being lean or gaunt).
In this sentence, 'khẳng' appears as part of the verb 'khẳng định', which means 'to affirm' or 'to assert' something strongly.
Cô ấy luôn khẳng định sự đúng đắn của mình.
She always affirms her correctness.
Here, 'khẳng' is used in the compound adjective 'khẳng khái', indicating someone who is straightforward and direct.
Anh ta có phong cách nói chuyện rất khẳng khái và rõ ràng.
He has a very straightforward and clear way of speaking.
In this example, 'khẳng' is employed to add emphasis, similar to 'undeniably' in English, though this usage is less common in contemporary conversational Vietnamese.