to believe - inanmak Its meaning changes depending on how you conjugate the stem; "inan" İnanıyorum. - I believe. İnanmıyorum. - I don't believe. İnanamıyorum. - I can't believe. İnanılmaz. - Unbelievable. ... Your example "inanırsan" literally means "If you believe."

believe's meaning is 'inanmak' you can use 'if you believe', it's meaning is 'inanırsan' so it's correct

to believe: farzetmek ,varsaymak.

Thank you all! Now it is more clear. Thanks again :)

'inanırsan' means second person conditional case in present.it exactly means 'if you believe' in english. if you ask 'to believe' in V1 form it's 'inanmak'. but we have some different usage of verbs by suffixes. radical is 'inan'. for instance i believe means 'ben inanıyorum' in turkish.