#Bash 74 Sed 65 + 4 bytes

65 bytes for the script and 4 for the r and f flags.

sed -r "s/\s*([.,?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i" s/\s*([,.?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i

Usage: Enter text, press enter and then Ctrl + D (send EOF).

Bash 74 Sed 65 + 4 bytes

65 bytes for the script and 4 for the r and f flags.

sed -r "s/\s*([.,?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i" s/\s*([,.?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i

Usage: Enter text, press enter and then Ctrl + D (send EOF).

#Bash 74 bytes

sed -r "s/\s*([.,?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i"

Usage: Enter text, press enter and then Ctrl + D (send EOF).

This should be straight up sed, but I can't get it to work properly... (Unknown command `.')

#Bash 74 Sed 65 + 4 bytes

65 bytes for the script and 4 for the r and f flags.

sed -r "s/\s*([.,?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i" s/\s*([,.?\!\"\':;\(\)A-Z])(\1|\s)*/\1/g;s/(he|she|it) is/\1\'s/i

Usage: Enter text, press enter and then Ctrl + D (send EOF).