Learn Hardcore Romanian: Copiii traversează podul vechi după școală. - The children cross the old bridge after school.

“Traversează” is the 3rd person present indicative of the 1st-conjugation verb a traversa (to cross). In Romanian, both singular and plural 3rd-person forms share the ending -ă:
• El/Ea traversează (he/she crosses)
• Ei/Ele traversează (they cross)
Since the subject is copiii (the children), here it means “they cross.”

Why is podul spelled with “-ul” at the end, and what does that indicate?

In Romanian the definite article is attached to the end of the noun.
• pod = a bridge (indefinite)
• podul = the bridge (definite)
So podul vechi literally means “the old bridge.”

Why isn’t there a marker “pe” before podul, even though it’s a definite direct object?

The preposition pe is used before definite animate (usually human) direct objects:
• Îl văd pe băiat = I see the boy
Bridges are inanimate, so you omit pe:
• Copiii traversează podul = The children cross the bridge

Why does the adjective vechi come after the noun, and why doesn’t it change its ending?

Attributive adjectives in Romanian typically follow the noun:
• podul vechi = the old bridge
When the noun carries the definite article (-ul), the adjective remains in its base (uninflected) form. You could also say vechiul pod, but podul vechi is the common order.

What does după mean here, and which case does it govern?

după is a preposition meaning after (in time) or behind (in space). It governs the accusative case. In this sentence it expresses a time relation:
• după școală = after school

Why is there no article before școală in după școală?

When you use după to express time, Romanian normally omits the article—just like English “after school,” not “after the school.” Thus școală remains bare.

Why does copiii have three i’s, and how is it pronounced?

“Copiii” = copil (child) + plural suffix -i + definite article -i. All three letters merge into copiii. Pronunciation is roughly [ko.pi.’i], with a long “i” at the end (often heard as two or three short “i” sounds in rapid speech).

Can I change the word order? For example, is După școală, copiii traversează podul vechi also correct?

Yes. Romanian word order is fairly flexible. Placing the time phrase first simply shifts the emphasis:
• După școală, copiii traversează podul vechi.
You can even insert commas for clarity:
• Copiii, după școală, traversează podul vechi.