Add the following line to your ~/.bashrc:
alias sudo='sudo '
From the bash manual
Aliases allow a string to be substituted for a word when it is used as
the first word of a simple command. The shell maintains a list of
aliases that may be set and unset with the alias and unalias builtin
The first word of each simple command, if unquoted, is checked to see
if it has an alias. If so, that word is replaced by the text of the
alias. The characters ‘/’, ‘$’, ‘`’, ‘=’ and any of the shell
metacharacters or quoting characters listed above may not appear in an
alias name. The replacement text may contain any valid shell input,
including shell metacharacters. The first word of the replacement text
is tested for aliases, but a word that is identical to an alias being
expanded is not expanded a second time. This means that one may alias
ls to "ls -F", for instance, and Bash does not try to recursively
expand the replacement text. If the last character of the alias value
is a space or tab character, then the next command word following the
alias is also checked for alias expansion.
So Bash only checks the first word of a command for an alias, any words after that are not checked. That means in a command like sudo ll, only the first word (sudo) is checked by bash for an alias, ll is ignored. We can tell bash to check the next word after the alias (i.e sudo) by adding a space to the end of the alias value.