This is the 459th most frequent Finnish word.
hyvinkin
"Hyvinkin" means "quite possibly" or "even very."
In this case, 'hyvinkin' is utilized to emphasize 'ajoissa' (on time), suggesting a possibility of being even earlier than typical timing.
Hän saattaa saapua hyvinkin ajoissa.
He might arrive quite early.
Here, 'hyvinkin' enhances the adjective 'hyödyllisiä' (useful), showing a higher probability or intensity of usefulness.
Kielioppiharjoitukset voivat olla hyvinkin hyödyllisiä.
Grammar exercises can be extremely useful.
The word 'hyvinkin' emphasizes the possibility or likelihood of something being the case.