The particle MONO DE is used to translate "because", "since", and is used the same way as the particles KARA and NODE. However, MONO DE is more formal. Check KARA and NODE for further information.
毎日忙しいもので、部屋が散らかっています。
まいにち いそがしい もの で、へや が ちらかっています。
Since I’m busy every day, my room is messy. / My room is messy because I'm busy every day.
If you have never learnt Japanese before or have questions, check out the F.A.Q. section from the link in the horizontal menu below the logo Japan-Activator