"I love this woman with sisu."
Translation:Rakastan tätä sisukasta naista.
First and second person pronouns (minä, sinä, me, and te) are optional. Third person pronouns (hän, se, he, and ne) are not optional. The problem I see with the answers shared above has to do with vowel harmony. You will never have a word with ä and u in it, like sisukastä, unless it is compound. The partitive ending -a/-ta goes with words that include a, o, or u (sisukas-->sisukasta). It becomes -ä/-tä when it is put on a word with ä, ö, or y (tyttö-->tyttöä). The vowels i and e are neutral and can go with either group. If they are the only vowels in a word, the ending follows the ä group (mies-->miestä). https://en.m.wikibooks.org/wiki/Finnish/Grammar-Vowel_harmony