With Excel when you want to concatenate strings you just use the overloaded plus sign, so =A3 + " Hello" whould add the string hello to whatever is in cell A3. With Google Sheets, this doesn't work, you need the use the ampersand, so =A3 & " Hello" makes sense given the different heritages. One is from the 1-2-3 world and the other from the Javascript one.