See the attached image:
I am having a difficult time grading this paper as I am not sure if the student intentionally wrote the answers in such a way that each answer looks like both "T" (or "t") and "F" (or "f") or if it is just his normal style of writing. He did a terrible job in answering other questions, if this information is even relevant.
How should I grade this student's answer? (The correct answers are "F", "T", "T", "T", and "F".) If the student intentionally wrote ambiguously, should I give him zero for all these five questions? If yes, how to prove that he did this intentionally?
How should I design my questions to prevent this from happening in the future?
Edit 2022-03-04. Mystery solved! I have talked to the student and he admits that he wrote his answers in frustration. His intended answers are TTTFT. Many thanks to everyone for your input.