"She has a Finnish cell phone."
Translation:Hänellä on suomalainen kännykkä.
I think so. Although puhelin (telephone) can mean old landline telephones, these days in Finnish it mostly refers to mobile phones.
So to sum it up:
- puhelin can mean both cell phones and old landline phones, but landlines aren't really available here anymore.
- Kännykkä refers exclusively to cell phones but the word has old ring to it and has fallen mostly out of use these days, especially by younger people.
At least in Helsinki and Oulu, where I work (with numerous ex-nokia employees) we use puhelin. I have never heard this term in 15 years of living in Finland.
That said, it may be used around people who do NOT work in the telephone business.
This likely explicitly means 'cellphone' despite that being the only type of phone one can now have in Helsinki. (It is not possible to order a residential land line any longer.)
No, it wouldn't. Finnish here refers to nationality, not language.
Hänellä on suomeksi kännykkä would be interpreted as "the user interface of the phone is in Finnish", and the correct way to say that would be hänen kännykkänsä on suomeksi (his cell phone is in Finnish).
In Finnish, all nationalities (suomalainen, a Finn, Finnish made) and languages (suomi, Finnish) are written in lowercase. So Suomeksi, with the capital letter, actually refers to the country Finland. Hänen kännykkänsä muuttuu Suomeksi would mean "his cell phone is turning into Finland" :^)