if it's a trademark of the same category, it can't be registered basically. if it's a trademark of the same category but the small group is different, you can still apply for registration. It also depends on whether the original trademark was used by myself or by another person. If it is another person's trademark, it is still in the same category. Adding new words to it is likely to cause trademark infringement, which is easy to misunderstand.
Article 57 of the Trademark Law commits any of the following acts, which are all violations of the exclusive right to use a registered trademark:
(1) using a trademark identical to its registered trademark on the same commodity without the permission of the trademark registrant;
(2) without the permission of the trademark registrant, using a trademark similar to its registered trademark on the same commodity, or using a trademark identical to or similar to its registered trademark on similar commodities may easily lead to confusion;
(3) selling goods that infringe upon the exclusive right to use a registered trademark;
(4) Forging or unauthorized manufacturing of registered trademark marks of others or selling forged or unauthorized registered trademark marks;
(5) changing its registered trademark without the consent of the trademark registrant and putting the goods with the changed trademark on the market again;
(6) intentionally providing convenient conditions for the infringement of the exclusive right to use a trademark of others and helping others to commit the infringement of the exclusive right to use a trademark;
(7) causing other damage to the exclusive right to use a registered trademark of others.