For instance, in držati, držimo, drž is the stem, “ti” is the infinitival ending, “mo” is the 1st person plural ending, and “a” and “i” are theme vowels – so this cell should contain “a,i” (the order is always infinitive stem first, present stem second). For gledati, gledamo, this should be “a,a”. For pisati, pišemo “a, je”.
Verbs with obvious root allomorphy (klati, koljem) should be added to the most frequent class they fit into (in this case either a, je or /,e).
For kupovati,kupujem the combination “ova, uje” should be entered, even though it is possible that the actual thematic vowels are only “a, je” or “a, e”.
Brinuti / brinem yields “nu, ne” (the order is always infinitive stem first, present stem second).
When it is unclear whether the theme vowel is e or je (in particular in the combination a, je, as in orati - orem - where r is known to be able to absorb j, or smejati se - smejem se, where the j from the stem can absorb the j of the theme vowel) - always go for je (i.e. enter: a, je).