1.) Since there are only two grades better than C, what Kyle is saying is that Ben is a B student and Amy is an A student.
2.) Only D and F students can be liars, so the only way for one liar to get better grades than another student is for one to be a D student and the other to be an F student. So according to Ben, Anne is a D student and Jack is an F student.
3.) Ben told you that Anne is a liar, so the F students in Rows 1 and 2 must not be adjacent to each other. Josh might be a liar. He says that Eric and Jen are not equal students. If they were equal students, they could not both be F students, since we have established that Anne is a liar. If Eric and Jen were equal and not F students, then Maya and Kurt would both have to be F students, since Amy is not adjacent to an F student and every row has one. But that would mean Anne is telling the truth, but again, we know from Ben that she is a liar. Since Eric and Jen cannot be equal students, Josh must be telling the truth, so it is also true that Kurt is an A, B, or C student. Therefore the F students in Rows 1 and 2 are Maya and Jen.
4.) Maya is a liar, so Lily is anything but a C or D student. We also know, according to Jack that at least one column must go ABCDF or FDCBA. Column 1 cannot because Kurt cannot be a D, according to Josh. Column 2 cannot because John cannot be an F according to Amy and Lily cannot be a D according to Maya. The only column that could go in order, therefore, is the fourth column. And according to Amy, it must go ABCDF.
5.) Kurt must be A, B, or C according to Josh. Lily must be A, B, or F according to Maya. According to Cait, Kurt and Lily are the same, so they must both be either A or B. This means that no row can have three students who get better grades than Lily, because no row can have three A students, according to Phil. Therefore, according to Nate, Eric is a C student.
6.) Kurt is either A or B. Since Row 1 can only have one B, according to Eric, Kurt must be an A student.
7.) According to Cait, Lily is also an A student.
8.) Row 1 has only one unknown cell, and no B or D. This means that Lee is lying. He cannot be an F student, since Mike in the same row is an F student; therefore Lee must be a lying D student.
9.) Since Lee is a liar, Eve must be telling the truth. Therefore, according to Eve and Phil, Zach and Tara are both C students.
10.) Tara says that Kurt and Seth are both adjacent to at least one additional male C student. John cannot be a C student because his row already has two, so either Jake or Greg is a C student. This means that Row 3 already has two C students: Jake/Greg and Nate. So Seth needs to be adjacent to at least one more male C student (besides Nate) and it can’t be Evan. Therefore Dan must be a C student.
11.) Having just established that Jake or Greg is a C student, Dan tells you that the other one is a B student, and so is Evan.
12.) According to Evan, John cannot be a D student. He also cannot be an A or C student because his row already has two of those. He cannot be an F student because his row already has one. Therefore John must be a B student.
13.) According to John, Ruth cannot be an A or D student. Her row already has an F student. And according to the liar Jen, Ruth cannot be a C student; therefore Ruth must be a B student.
14.) You know that row 3 has two B students (Dan), so if any other row has two B students, it is row 4. This means that no one other than Ruth in Row 5 is a B student. According to John, Katy is also not a D or A student. Her row already has an F student, so Katy must be a C student.
14.) Similarly to above, Lyla cannot be an C, D, or F student according to John. She cannot be a B student according to Ruth. Therefore Lyla must be an A student.
15.) According to John, Liz cannot be an A, B, C, or F student. This leaves only D.
16.) If Seth is a B student, Liz’s first clause is a lie, but the F in Row 4 would have to be Jane, so Liz’s second clause would be true. Either she is all truth or all lies. If Seth is an F student, then Liz’s first clause is true but her second clause would be a lie. Since Liz cannot be fully lying, she must be telling the truth. Therefore Jane is an F student.
17.) Seth cannot be an F student since his row has one. He cannot be a D student since his row has two. He cannot be an A student since he is adjacent to Lyla (John). He cannot be a B student according to Liz. Therefore he must be a C student.
17.) Tara is a C student and is currently adjacent to two C students. We know that Jane is a liar, so Greg must be a C student.
18.) According to Dan, Jake must be a B student.