Learn Portuguese (Portugal): O aniversário dele é em maio.

In Portuguese, to say 'his' or 'hers', it is very common to use dele (of him) or dela (of her) after the noun. So O aniversário dele literally translates to 'The birthday of him'. This is often preferred over the possessive word seu because seu can mean 'your', 'his', 'hers', or 'theirs', which can get confusing!

Why is there an O at the very beginning of the sentence?

Because the phrase is structured as 'The birthday of him', we need the definite article O (The) at the start. When using dele or dela to show possession, you must include the article that matches the noun—in this case, the masculine singular word aniversário.

Why do we use é here instead of está?

é comes from the verb ser, which is used for permanent facts, dates, and times. Even though a birthday happens once a year, the date itself is a fixed, permanent characteristic of the person. The verb estar is used for temporary states, so it wouldn't fit here.

Why is maio written with a lowercase 'm'?

In Portuguese, the months of the year (like maio, abril, dezembro) and the days of the week are always written with lowercase letters. This is a small but important difference from English capitalization rules!