ihmettää - Wiktionary, the free dictionary

¹⁾ Used only with a possessive suffix.

²⁾ Usually with a possessive suffix (active only).
³⁾ Some uses of the verbal noun are called the 'fourth infinitive' by certain sources (more details).
⁴⁾ Usually with a possessive suffix. May not be used with all verbs, especially intransitive ones (more details). Distinct from nouns with the -ma suffix and third infinitive forms.

* The third-person singular indicative form ihmettää does not exhibit final gemination,
unlike the first infinitive (the lemma form), even though they are spelled identically.