Foreign language skills in international development: What’s in demand

Foreign language skills can give you an edge as you’re applying for international development jobs or consulting gigs, and they may even affect your pay. But, which languages are in high demand – apart from English, which most aid groups require applicants to speak fluently?

Is it worth learning one of the major languages like French and Spanish, which are suitable for many countries but won’t make you “stand out” as much as a local? Or is it more beneficial to become proficient in a lesser-known language?