Breakdown of Haluan nähdä sen omin silmin, jotta olen varma.
olla
to be
se
it / he / she (of a person) / that
varma
sure / certain
haluta
to want
Questions & Answers about Haluan nähdä sen omin silmin, jotta olen varma.
How does the instructive case work in the phrase omin silmin?
The instructive case uses the plural ending -in to express 'by means of' or 'using'. Here, silmin means 'with eyes'. The adjective modifier oma (own) must agree with the noun, so it also takes the plural instructive ending, becoming omin. Together, they form the fixed phrase omin silmin (with one's own eyes).
Why doesn't omin silmin have a possessive suffix attached to it?
In fixed phrases using the instructive case, possessive suffixes are almost never used. The ownership is already implied by the word oma (own) and the context of the sentence, so adding a suffix like -ni (my) is unnecessary and would sound unnatural.
Why is the object sen instead of the partitive sitä?
The verb nähdä (to see) takes a total object when the action is complete and the sentence is affirmative. Since you want to see the whole thing to be sure, the pronoun se takes the genitive-accusative form sen. If the sentence were negative (I don't want to see it), it would take the partitive form sitä.
Could I use the conjunction että instead of jotta here?
You could, and native speakers sometimes do in casual speech, but jotta specifically means 'in order to' or 'so that', indicating a clear purpose. Että just means 'that', so using jotta makes the cause-and-effect relationship much clearer and represents better Finnish style for this context.