sure; certain; reliable; trustworthy; If I'm not mistaken; If I remember correctly
to ascertain; to check; to make sure
unreliable; uncertain; indefinite; unclear
confirmation; certification; ascertainment
to make sure of the truth
don't do anything rash!; keep composed!
established (certain) fact
to strengthen; to beef up; to put on a firm basis; to ensure; to secure
to brace oneself; to keep one's spirits up; to keep one's composure; to pull oneself together; to stay strong
checking (e.g. result of calculation)
probability; likelihood; chances