Use chown to set the ownership of all a folder's subfolders and files?

How can I use the chown command to change the ownership of all a folder's subfolders and files?

From chown --help:

Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...
  or:  chown [OPTION]... --reference=RFILE FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP.

[...]

  -R, --recursive        operate on files and directories recursively

[...]

So you need to run (probably with sudo):

chown -R USERNAME:GROUPNAME /PATH/TO/FILE

Or, if the group shall be the specified user's primary group (usually same name), you can also omit the GROUPNAME and just give the USERNAME: with a colon (no space before it!). It will be set implicitly:

chown -R USERNAME: /PATH/TO/FILE

To only change the user and leave the group as it is, just specify USERNAME and no group name and no colon:

chown -R USERNAME /PATH/TO/FILE

To only change the group and leave the owner user as it is, just specify :GROUPNAME with a leading colon:

chown -R :GROUPNAME /PATH/TO/FILE

My username is timo and I did this to take ownership to all my files and folders on home directory (transferred from another account):

~$ sudo chown -R timo /home/timo/*