"A giraffe is taller than a lion"
Translation:Twiga ni mrefu zaidi ya Simba
As I have always understood it, kuliko literally means "where there is" so the sentence means "A giraffe is tall where there is (i.e., compared to) a lion" => "A giraffe is taller than a lion." I don't see how there is any role for an object infix here. I do see glosbe.com gives a couple of examples of kumliko, but a large proportion of their source material comes from translated religious tracts, so bado nina shaka na neno hilo "kumliko". Labda hili ni moja katika mabadiliko ya hivi karibuni katika lugha ya Kiswahili ??
Edit: Although it is not taught in this course, the verb kushinda is sometimes used for comparisons (at least it used to be), because one of its meanings is "to surpass", e.g., Juma amenishinda katika mtihani wa hisabati. ~ Juma got a better grade than I in the math exam. Since -shinda often takes a direct object, in a comparison it would not be surprising to find Twiga ni mrefu kumshinda simba. I seem to recall that the verb kupita is (or used to be) sometimes used in comparisons, in the same way as kushinda