How can I concatenate two fields in a view?
Let's say you have field A, and field B.


Make sure A, comes before B in the fields list.
Edit field A, and check "Exclude from display". The field will now no longer show up.
Edit field B, find the checkbox for "Re-write the output of this field".
Below the new textbox, find "Replacement patterns." There you should now be able to find something that looks like [field-A], and [field-B], with possibly many more options.
Enter "[field-A] [field-B]" as the replacement pattern.


And you should have the fields concatenated.

There are some situation, where the markup generated by Views with this configuration is not desirable, as you will now have A "inside" B. If that's a problem, one can add a completely new dummy field, of type "Global: text", and to steps 3, 4 and 5 on that field instead.