The difference between 'eri', 'ero' and 'erilainen'

What is the difference between eri and erilainen?

Eri is something that is a completely different thing, object or matter.  The word eri doesn't get any endings.

• Tämä on ihan eri asia! - This is a totally different thing! (You cannot even compare them.)
• Tämä on eri kirja. - This is a different book. (You should get another one.)
• Hän soitti eri paikasta kuin aikaisemmin. - He called from different place than before. (Not just different in style, but completely a different location.)

Erilainen is different kind and behaves like any adjective:

• Tämä kirja on vähän erilainen. - This book is a little bit different.
• Tästä päivästä tuli erilainen kuin kuvittelin. - This day became different than I imagined. 
• Kokeillaan jotain erilaista!  - Let's try somehing different!
• Sinä tuoksut erilaiselta kuin yleensä. - You smell different than usually.

Ero is a difference or a divorce.

• Mitä eroa näillä on? - What's the difference between these?
• Mitä eroa on sanoilla eri ja erilainen? - What's the difference between the words eri and erilainen?
• Ensin tuli vauva, sitten ero. - First came a baby, then a divorce. 

Related posts and a song for you to listen to:

• Ero, erota and erottaa
• Erikoinen - Erityinen
• Mikä - Mitä
• Erilaiset by Robin

About the author of Random Finnish Lesson: 

My name is Hanna Männikkölahti. I am a professional Finnish teacher who gives private online lessons and simplifies books into easy Finnish. Follow this blog, if you want to be the first one to know when I post something new.  If you want to subscribe to my newsletter, you can do it here.