Difference between to apply and to apply to in Korean
신청하다·지원하다

신청하다to apply
신청하다 means to apply or to sign up for something. You use it when you ask for a class, a card, a job, a service, or another official thing. It is often used with forms, websites, or offices.

지원하다to apply to
지원하다 means to apply to a school, job, club, contest, or another opportunity. You use it when you want to join, enter, or get something, so you send your information or a form. For example, you can apply to a company, a university, or a part-time job.
The difference
to apply (신청하다) and to apply to (지원하다) are nearby Korean vocabulary items learners often meet together. Use “to apply” when 신청하다 means to apply or to sign up for something. You use it when you ask for a class, a card, a job, a service, or another official thing… Use “to apply to” when 지원하다 means to apply to a school, job, club, contest, or another opportunity. You use it when you want to join, enter, or get something, s…