を
o
を is not the object marker. It is the path.
The picture A line your action sweeps along. Whatever that line touches takes を. を is the line an action sweeps along; に is the single point it lands on.
Where the picture shows up in を
-
what you take hold of
お弁当を買いました。
obentō o kaimashita
I bought a lunch box.
A lunch box lifted off the shelf and travelling with your hand into the basket
-
what you work on
この書類をコピーしてください。
kono shorui o kopī shite kudasai
Please make a copy of this document.
The document pressed flat on the copier glass as a bar of light sweeps across it
-
the path you sweep along
毎朝この道を歩きます。
maiasa kono michi o arukimasu
I walk down this street every morning.
Footprints laid in a row from one end of the street to the other
-
the place you come out of
七時に家を出ます。
shichi-ji ni ie o demasu
I leave the house at seven.
The front door swinging open and a body passing out through the frame
-
the stretch of time you pass through
長い冬を過ごしました。
nagai fuyu o sugoshimashita
We got through a long winter.
Three calendar pages turning one by one as the winter is crossed
Understand and like take が in Japanese, not を: 日本語が分かります。
All of it in one picture
を is the line your action leaves behind it. Take the lunch box and the line stops at the object; copy the document and the line sweeps once across the paper; walk the street and the line stretches out along it. Step outside and the line runs from inside the house to out; get through a winter and the same line is drawn over time instead of ground. So stop asking what を means and ask what the action swept through — all five answers are one line.