This is the 64th most frequent Estonian word.
kindlasti
Certainly; definitely; surely.
In this context, 'kindlasti' is used to convey confidence in the person's ability to understand.
Ta saab kindlasti aru, mida sa mõtlesid.
He/She will certainly understand what you meant.
Here, 'kindlasti' emphasizes the strong recommendation or certainty regarding the action of taking an umbrella.
Kindlasti on vaja võtta vihmavari, kuna võib hakata vihma sadama.
It is necessary to definitely take an umbrella, as it might start raining.
In this sentence, 'kindlasti' is used to express certainty about the speaker's intention to go to the library.