tuulilasiin

Tuulilasiin is the illative singular form of the Finnish noun tuulilasi, meaning the windshield of a motor vehicle. Tuulilasi is a compound of tuuli (wind) and lasi (glass) and refers to the pane of glass that protects vehicle occupants from wind, debris, and weather. In standard Finnish, tuulilasi is used specifically for the windshield on cars, trucks, and other road vehicles.

Grammatical note: Finnish nouns decline in cases. The illative form tuulilasiin denotes movement toward or into the windshield, and is commonly used with verbs of motion, perception, or manipulation. For example, "Hän kurkisti tuulilasiin" means "He peered into the windshield." Other case forms include tuulilasin (genitive), tuulilasiin (illative), tuulilasis-sa (inessive: tuulilasis-sa), and tuulilasilta (partitive-like forms vary by dialect). More typical in everyday language are phrases that refer to the windshield with other cases, such as "tuulilasin kunto" (the condition of the windshield).

Usage: In everyday Finnish, tuulilasiin appears in contexts involving directing attention toward or into the windshield, or describing actions related to the windshield. It is not specialized jargon; most speakers understand it as the illative case of tuulilasi. For general reference to the windshield itself, the base form tuulilasi is commonly used, while possessive or descriptive phrases use genitive or other cases as appropriate.