you have oral exams in both languages at the end of your first year; if you're taking a subject ab initio, you will have another oral (i.e. the 1A oral, when you catch up with the post alevel lot) in your second year as well.
Oral exams usually take the following format; you're given a passage, usually on something topical (mine was on 'Denglish' for German, and recycling and the environment in Italian). You get 15 mins to read and prep points for discussion.
In the exam, you'll be asked to read a couple of lines aloud- to break you in and check your intonation etc carefully - summarise the passage briefly, and then there'll be some questions. It's designed to work out like a dialogue between you and the examiners - with most exams of this nature, you can probably steer it in the direction you want by not shutting up

Oh, and there will be two examiners in the room. Usually one native speaker and one english/other, but that's not the case 100% of the time. One of them will mark content, the other grammar, which are weighted equally.
The oral itself, however, is worth half of the translation paper - you'll sit six papers overall, so it works out at something silly like 8.3%. Still worth doing well on though to boost everything else.
that's probs more than you wanted to know, sorry! anything to avoid an essay though....