Learn Croatian: Majstor je popravio pokvarenu cijev. - The repairman fixed the broken pipe.

Cijev is a feminine noun, even though it ends in a consonant. Like other feminine nouns of this type (such as stvar or noć), its accusative form is exactly the same as its nominative form. However, any adjectives attached to it still need the regular feminine accusative ending -u, which gives us pokvarenu cijev.

Is majstor the standard word for a repairman? It looks a lot like the English word 'master'.

Yes! While it originally means 'master' or 'craftsman', in everyday Croatian majstor is the most common, go-to word for any kind of handyman, mechanic, or repairman who comes to your house to fix something.

Why is the verb popravio used here instead of popravljao?

Popravio comes from the perfective verb popraviti, which shows that the action was successfully completed. The pipe is fully fixed. If you used the imperfective form popravljao, it would mean the repairman was in the process of fixing it, but might not have finished the job.