|Kotus type 29 (lapsi)||NSK types 45 (lapsi), 46 (hapsi) and 50 (uksi)|
A very small number of nominals ending with a hard consonant followed by ⟨-si⟩. No consonant gradation.
The word ⟨lapsi⟩ is the only word always declined like this. A few other words may decline either like ⟨lapsi⟩ or like type 7 (ovi) (the two declensions differ only in the partitive singular and genitive plural).
Inflectional stem replaces ⟨-i⟩ with ⟨-e-⟩. ⟨-e-⟩ of stem dropped before plural marker ⟨-i-⟩.
When the partitive singular ending ⟨-ta⟩/⟨-tä⟩ and genitive plural ending ⟨-ten⟩ are attached, the consonant before the ⟨s⟩ is dropped. Genitive plural ending ⟨-en⟩ also possible. Partitive plural ending ⟨-a⟩/⟨-ä⟩.