i just learn linux, i want to ask how to create an user with more than 1 secondary group?
thank for response

Are you using the useradd command to create your users? If so, the -G switch is for specifying secondary groups. For example:
Have a look at the man page for useradd for more info; man useradd

if the question is create user jack with secondary group manager, sysadmin, admin and web dev could i use this command:
useradd -c jack -G manager,sysadmin,admin, webdev -s /bin/bash jack

if the question is create user "jack" with secondary group manager, admin, sysadmin,webdev can i use this command:
useradd jack -G manager, admin, sysadmin, webdev -s /bin/bash jack

regard
levis

can you explain me what is creating user with secondary group

Normally when you create a user they are also added to a group (their primary group) with the -g switch.

Secondary or supplementary groups are often used so that multiple users can access the same directories. They can also be used to provide access to devices (sound cards, cdroms, etc.).

For example, my home directory is owned by my user account and my primary group - there are no other members of the group that owns my home directory. However, I am also in a developers group (a secondary group) so that I can access the documentation the developers in my area use.

Thanks for your clarification