Selective Forwarding Q

[April]

If I set up Selctivel Forwarding to resolve anything.com, which
contains something1.anything.com and something1.anything.com two
subdomains, on a server A which is authoritative for
something1.anything.com to use server B as Forwarder.

What will happen when I try to send queries to server A to look up
names in something1.anything.com and something2.anything.com.

Would server A, resolves names in something1.anything.com
authoritatively/locally, and forward names in something2.anything.com
to server B, and server B will try to find the authoritative server to
resolve and send the answer back?