Learn Farsi: من دوره‌ی چهارم را شروع می‌کنم.

In Farsi, you can form ordinal numbers by adding the suffix -om to a regular number. Since four is chahār, adding -om gives us chahārom (fourth).

Why does chahārom come after the noun here?

When ordinal numbers end in -om (Type 1), they act like regular adjectives. That means they must come after the noun they describe. They are connected to the noun using the Ezafe vowel, just like any standard noun-adjective pair.

Why does dowre (course) have an extra letter at the end to make it dowre-ye?

The word dowre ends in a silent 'h' (which makes a short 'e' sound). Because the word ends in a vowel sound, the Ezafe connecting it to the adjective is pronounced -ye. In modern writing, we show this by adding the letter 'ye' (ی) to the end of the word, making it دوره‌ی (dowre-ye).

Why is the object marker rā (را) placed after chahārom rather than directly after the noun?

The word rā marks a specific direct object, but it attaches to the entire noun phrase, not just the first word. Because 'the fourth course' is a single phrase (dowre-ye chahārom), rā goes at the very end of that entire group.

What kind of verb is ?