How i can to delete all after last word no.4?

word1 word2 word3 word4 word5
word6 word7 word8 word9
word10 word11 word12 word13 word14 

So i want to remove word5 and word14

• Ctrl+H
• Find what: ^(?:\S+\h+){4}\K.*$
• Replace with: LEAVE EMPTY
• check Wrap around
• check Regular expression
• UNCHECK . matches newline
• Replace all

Explanation:

^               # beginning of line
  (?:           # start non capture group
    \S+         # 1 or more non space character
    \h+         # 1 or more horizontal space
  ){4}          # end group, must appear 4 times
  \K            # forget all we have seen until this position
  .*            # 0 or more any character but newline
$               # end of line

Result for given example:

word1 word2 word3 word4 
word6 word7 word8 word9
word10 word11 word12 word13 

Before:

After: