Being Afraid Of
To say that you are afraid of someone or something, use the reflexive verb bać się (to be afraid). In Polish, this verb is followed directly by the Genitive case, without any prepositions.
| She is afraid of snakes because they are dangerous. | Ona boi się węży, dlatego że są niebezpieczne. |
| Are you afraid of spiders, sir? | Boi się pan pająków? |
You will also use the Genitive case when talking about fearing abstract concepts, such as heights (wysokość), pain (ból), or loneliness (samotność).
| I am afraid of heights, that's why I won't fly. | Boję się wysokości, dlatego nie polecę. |
| The patient is most afraid of pain and loneliness. | Pacjent najbardziej boi się bólu i samotności. |
Being Happy About
When you want to express that you are happy or rejoice about something, use the reflexive verb cieszyć się along with the preposition z (which translates here to about or from). Just like bać się, the preposition z in this context requires the following noun to be in the Genitive case.
| He is very happy about the good grade. | On bardzo się cieszy z dobrej oceny. |
| We are happy about your return because we love you. | Cieszymy się z twojego powrotu, dlatego że cię kochamy. |
| They are very happy about the wedding invitation. | Oni bardzo się cieszą z zaproszenia na wesele. |
Putting It Together
Because both expressing fear and expressing happiness about something require the Genitive case, you can easily link these emotional reactions together in your sentences.
| I am afraid of loneliness, that's why I am happy about his return. | Boję się samotności, dlatego cieszę się z jego powrotu. |