Learn Finnish: Pohdin tunteitani kirjoittamalla. - I ponder my feelings by writing.

In Finnish, you can often drop the first and second person genitive pronouns like minun (my) or sinun (your). The possessive suffix -ni at the very end of tunteitani already makes it perfectly clear whose feelings they are. While minun tunteitani is grammatically correct, omitting the pronoun is extremely common and natural.

Why is the object tunteitani in the partitive case?

The verb pohtia (to ponder or reflect) describes a continuous, ongoing thought process rather than an action with a clear endpoint. Because the action is irresultative, it requires a partitive object. We take the partitive plural tunteita (feelings) and attach the possessive suffix -ni.

How is kirjoittamalla formed to mean "by writing"?

This uses the third infinitive, also known as the MA-infinitive. We take the stem of kirjoittaa (to write), add -ma to get kirjoittama, and then add the adessive case ending -lla. Using the adessive case with the third infinitive is the standard way to say you achieve something "by doing" an action.

Why does the t change to a d in the word pohdin?