How do I work out which term is more commonly searched, workforce productivity vs workforce efficiency

[MobileDay]

Trying to discover which one people are more likely to plug into a search engine.

[Linda-Vassily]

Yes those tools are good and the comment about intent is right on the money too. [Apple might have a high search volume, but that's not necessarily as helpful as you might think, if you are a fruit seller.]

One thing I like to do when looking at various keywords is to put them in Moz's keyword tool and see which sites are ranking.

This tells you something about intent (the sites that rank highest for a search term are likely to be the most closely aligned with user intent) and about competition (the tools shows you some metrics about the ranking domains). It doesn't help to pick a term with a high search volume if the competition is way out of your league.

[CommT]

John's right, but you need to work out what the search intent for each term is - and presumably pick the one that more closely matches your goals - this video is worth a watch: https://moz.com/blog/google-may-use-your-behavior-to-impact-search-rankings-whiteboard-friday

[ClaytonJ]

There are several methods - adwords keyword planner - or I use semrush.com. If you use semrush, it allows you some free searches. You need to choose your country that you are focusing on.  A site for useful tools is website-tools.net - that provides a few more.

Let me know if need any more assistance.