Is "a stitch in time saves nine" qualitative or quantitative?
Numerically it is quantitative, grammatically it is qualitative.
"Quantitative" refers to specific measurable amounts. Taking a stitch to be a unit (with arbitrary length) a comparison is made between one and nine, although again, the time period is not defined.
"Qualitative" refers to general characteristics that are not necessarily measurable except possibly in relative terms. Because a stitch is not specifically defined (although the mechanism may be familiar) and the time period is not either, it may be difficult to actually quantify this statement.
Furthermore, as it is an expression intended to reflect a more general principle (it is not really a "Chemistry" topic question, but a grammatical one) beyond stitches or numbers, it is entirely qualitative in stating generally that doing a small amount of something earlier can eliminate a need to do a large amount of it at some unspecified later time.