Learn Polish: Anna nie mogła zdążyć, dlatego że pociąg miał opóźnienie. - Anna couldn't make it in time because the train had a delay.

The verb móc (to be able to) has a stem change in the past tense. For a masculine singular subject, it's mógł (with an ó). But for feminine and neuter subjects, that ó changes to a regular o. Since Anna is a woman, the ó drops out and we use the feminine form mogła.

Does zdążyć always mean "to make it in time"?

Yes! Zdążyć is a very useful verb that means "to manage to do something on time" or "to catch" (like a train or a bus). You don't need to add any extra words for "time" in Polish—the verb itself carries that whole meaning.

Could I just say bo instead of dlatego że?

Yes, you could just say bo (because), and it would be perfectly natural. Dlatego że literally means "for the reason that." It is a slightly longer, slightly more formal way to say "because" that emphasizes the cause of the delay. You will hear both very often.

Why does the train use the masculine past tense miał if it's not a person?