using wildcards

me@box:~$ cat demo.txt

there is over thinking, and there is overthinking.

me@box:~$ cat demo.txt | egrep ‘the.*’

there is over thinking, and there is overthinking.

me@box:~$ cat demo.txt | egrep ‘over *thinking’

there is over thinking, and there is overthinking.

me@box:~$ cat demo.txt | egrep ‘over +thinking’

there is over thinking, and there is overthinking.

me@box:~$ cat demo.txt | egrep ‘(over )+the’

the quick brown fox jumps over the lazy dog