Pattern languages

I’ve found some brilliant patterns on the internet but there are terms I’ve not seen before, such as BO, sport weight and PM. Can you tell me what these mean? Jackie Roberts, Lincoln

Free patterns are abundant on the internet and many of these are American, so you may well find they do things differently. In the UK, we talk about 4ply and aran yarn; in the US, these are called sport weight and worsted. When we cast off in the UK, knitters across the pond ‘bind off’ (BO). PM is fairly universal but is usually written in full – it means ‘place marker’, which helps with matching up seams or denoting a corner. Also be warned that English versions of foreign-language patterns quite often lose something in translation! If you find an unfamiliar term on an internet pattern, you can usually find the answer on the internet, too. There is a lot of help out there!