Sometimes we want to label features like this:


We can do it by building the label expression using a tool we find under Layer>Label


We click "Label this layer" and then rather than selecting a field, we click on the Expression Builder


We build the expression for the label string, using fields and constants and operators and conversion functions. Note that the concatenation operator in QGIS is ||. We want our label to be on two lines so we insert a character that we will tell QGIS to treat like a "new line" signal. In this case we will use "/"


Back in the main dialog we can specify the new line character and play around with other stylizing options.