You can use several words eg Alan Mark beach will find all pictures with both Alan and Mark on a beach.
Give alternatives with the | key: eg Alan|Mark beach will find pictures of either Alan or Mark (or both) on a beach.
To exclude a word, use the ~ key: eg Alan ~Mark beach will find pictures of Alan but not Mark on a beach.
You can use months and/or years eg August 1994 will find all pictures from that month.
(But all photos from "May Christmas" can be found using May Christmas even if they were in April or June.)
There may be some false positives eg searching for Mark Lewis also brings up photos including Mark Willoughby and Andy Lewis.
To avoid this, try putting the words in speech marks eg "Mark Lewis".