Learn Italian: Sarai orgoglioso quando realizzerai qualcosa di bello. - You will be proud when you achieve something beautiful.

The verb essere (to be) has an irregular stem in the future tense, which is the focus of your current lesson. Instead of just dropping the final -e like regular verbs do, its stem changes completely to sar-. To say "you will be," you add the regular tu ending (-ai) to make sarai.

If I am speaking to a woman, does orgoglioso change?

Yes! Orgoglioso means "proud," and because it is an adjective, it must agree with the gender of the person you are describing. If you are speaking to a woman, the ending changes to match her gender: sarai orgogliosa.

Why does the sentence use the future tense realizzerai when the English translation says "when you achieve" in the present tense?

Italian is very strict and logical about time! Since the action of achieving hasn't happened yet and belongs in the future along with being proud (sarai), Italian uses the future tense after quando (when). English bends the rules and uses the present tense here, so be careful not to directly translate English habits into Italian.

Does realizzerai just mean "you will realize"?