arabic is a bit of a misnomer BSL - you have to get it to a high standard otherwise the signers get very upset at the system throwing a poor signer at them. so as someone has already said - maybe the basic words in a handful of languages. if you are targeting the area of newham , then perhaps ask newham council what languages they cover for the publications and the breakdown percentages. maybe that will give a target to aim for. perhaps they could even help you get started.