As a languages teacher, you can take a dictionary into the writing CA with Edexcel but the teacher is not allowed to correct. They can, however, give general feedback.
Glup, MFL GCSE is very different from O level and has changed a lot over the years I have been teaching it.
My own O level consisted of speaking exam (text to read aloud followed by a conversation, which was not pre-prepared); an essay exam (complete this story); a translation (French into English) and reading comprehension (questions in English); an aural exam (text/questions on tape, nothing written down and you weren't allowed to write the questions, just make notes); a dictation (1/4, 1/2 or full mark deducted for every mistake, including punctuation).
AQA GCSE in mid 1990s: 4 foundation exams (listening/speaking/reading/writing) and 4 higher exams as well for those who were capable. Listening and reading, all questions were in English; speaking was 2-3 role plays with 10 mins to prepare followed by a prepared conversation (on 3 topics out of 6); writing was not pre-prepared but you knew what topics were likely to come up.
GCSE now: Listening/reading exam at the end (worth 20% each) some questions/answers in MFL, some in English; speaking 2 x 4-6 min controlled assessments both pre-prepared, once topic is set there is no teacher input/correction allowed; writing is the same but 2 x 1 hour to write.
And this is the 3rd spec of GCSE that I have taught!