New to QGIS. Using point features as markers on a map imported from Google Earth. In my first shapefile layer the alphanumeric labelling worked fine. Added in a second layer and it is only allowing numerical labels? I noticed under layer properties, on the labels tab, the value is shown as 123 Labels (i.e. numeric), whereas for my other layer, the value is shown as abc Labels. Cannnot work out how to correct this?

Help appreciated![![enter image description here][1]][1]


  [1]: https://i.sstatic.net/XdE7s.jpg