Although most of the archives I work with are in English there are also a sprinkling of Latin documents. These generally fall into two groups: medieval deeds, and manor court rolls which were usually written in Latin until the middle of the 18th century.
I am old enough to have been at school when Latin was still widely taught in grammar schools and high schools and took Latin ‘O’ Level (the public exam taken by British students at age 16, since replaced by GCSE exams). At that time I had no idea that I would ever use Latin again. Later on I studied history at university, and as I specialised in the medieval period I took a short course in medieval Latin, dusting off my almost forgotten school Latin. I then went on to postgraduate work on medieval history, during which I learned to read documents written in abbreviated Latin script. Even then I had no idea that I would end up using the arcane skill of medieval palaeography as part of my job.
Latin documents may look alarmingly difficult, but in fact most of them follow a common formula. In their simplest form deeds will start out by telling you who is giving or selling land and to whom, then go on to describe the property and set out the terms of the transfer, before ending with a list of witnesses to the transaction. Once you know the basic formula and common phrases, making sense of a deed becomes much easier. Similarly with manorial documents: the contents of a court roll will follow similar patterns, and individual entries, for example when a new tenant is admitted to “copyhold” land (property held from a manor), will also follow a common formula. The most frustrating aspect of trying to read Latin documents is that they make extensive use of abbreviations; some of these can be learned, but others vary according to the individual scribe – often they simply left out what to the modern reader appear to be random groups of letters.
The starting point for most local historians or genealogists who decide to tackle Latin documents is often Latin for Local History by Eileen Gooder, which has been in print for over fifty years. There are also some good online tutorials like this one on Latin palaeography from the National Archives and this medieval palaeography tutorial at the Anglo-Saxon Online Hub. Tackling Latin documents may be a challenge, but it is by no means impossible, even for someone who has no prior knowledge of Latin.