Convert ISFJ to socionics
Your four letters are ISFJ
About eight minutes.
ISFJ does not convert to one socionics type, so this quiz decides between the three it can be: ISFp, ISFj and INFj. The 20 questions are chosen for your four letters and ask about the places those candidates actually differ, not the places the letters already agree.
Socionics writes the last letter small. It's not your MBTI letter.