How should I prepare for the MLAT?

The MLAT is essentially a test of knowledge of grammar and vocabulary. For the languages on the paper, there is typically a gap-filling exercise or one where you must choose between two words to complete a sentence, followed by some translations of sentences, either into English or into the language. The grammar portion will test specific areas of knowledge, and so there is often a trend in the kind of question which comes up. For example, languages with a subjunctive will almost definitely have a couple of questions regarding its formation, and those with a distinction such as between ser and estar will test if you are aware of the difference between the two. For the translation portion, I can only recommend that you go through vocab lists and find some more advanced vocab. There will be words there that you do not recognise, so do not panic if you can't translate every single word, just do what you can and make sure it makes sense. Going through the past papers found online will help with practice