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certain
In a sentence
Som si istý, že Tom na nás nezabudol.
I'm sure Tom hasn't forgotten about us.
Ja som si istý, že budeš spokojný.
I am sure that you will be satisfied.
Som si celkom istý.
I'm pretty sure.
Nie som si istý.
I'm not certain.
Examples from Tatoeba (CC BY 2.0 FR).
Source
Slovak National Corpus (SNK) ↗English gloss from the frequency publish path. Example sentences from Tatoeba (CC BY 2.0 FR).
Full attribution on References.