A plastic bag with old sports shoes. I probably left it somewhere in the hall outside the gym. The bag is white with a black logo on it and the shoes are blue snickers with green stripes.
If found, please call me on my mobile. The number is 111 222 333.
a plastic bag - reklamówka
a hall - korytarz
snickers - buty sportowe, 'adidasy'
a stripe - pasek