Learn Farsi: قدم می‌زدیم که انسداد جاده را دیدیم. - We were walking when we saw the blockage of the road.

انسداد (blockage) follows the 'en-C1-e-C2-â-C3' pattern. Its Arabic root is s-d-d, relating to blocking or closing. By placing these root letters into the template, it yields ensedâd (en-s-e-d-â-d), expressing the passive state of the road being blocked or closed off.

Why is که used here instead of وقتی که for 'when'?

While وقتی که means 'at the time that', using a simple که after a past continuous verb (like قدم می‌زدیم) is the standard Farsi structure to introduce a sudden interrupting event. It functions much like 'when suddenly' in English.

Why does the object marker را come after جاده instead of right after انسداد?

When a direct object is a noun phrase linked by the Ezafe vowel, the را marker must go at the very end of the entire phrase. The object of our seeing is the whole phrase انسداد جاده (the blockage of the road), so را anchors to the final noun.

What is the difference in nuance between قدم می‌زدیم and راه می‌رفتیم for 'we were walking'?

قدم زدن (literally 'striking steps') specifically implies taking a leisurely stroll or walking for pleasure. If the sentence used راه می‌رفتیم, it would sound more like the functional, physical act of traveling on foot.