있다 is a stative verb for "to exist" or "there is", whereas 가지다 is an action verb for "to take/have/possess". They both can be used to indicate possession but there are important differences arising from this fact. 1. 펜이 있어? is natural. 2a. 펜(을) 가져? doesn't make much sense, like "Do you (want to) take a pen? 2b. 펜(을) 가졌어? is okay but not the best. 2c. 펜(을) 가지고 있어? is the right way to indicate possession. The reason 2a doesn't work is because 가지다 cannot express the state of having something on its own. An indication of completion/result needs to be added, as in 가졌어. Even better would be -고 있다 which turns it into a continuing state. As for applicability, 가지다 is not limited to physical or concrete things. It is widely used for intangible things like occasion, personality traits, opportunity and all kinds of other things. (즐거운 시간을 가졌습니다, 인내심을 가지고 대처하다). It might be helpful to see the adjective forms of these verbs, i.e. when they come before a noun to describe it. - 펜을 가진 사람 is okay because the -(으)ㄴ ending adds the sense of a completion/result. - 펜을 가지고 있는 사람 makes the state even more clear, but -고 있는 is not absolutely necessary. - 펜이 있는 사람 is fine (Note 이 and 는). 있다 is already stative, so -(으)ㄴ is not necessary (it is actually wrong). Another difference between 가지다 and 있다 is how the possessed thing relates to the verb. The thing possessed is the object of the verb in 펜을 가지다, while it is the subject in 펜이 있다. Because Korean has a way of loosely connecting a descriptive relative phrase with a noun, this type of structures are natural and common. - [펜을 가진] 사람 = someone [who HAS a pen]. "pen" is the object of "has". - [펜이 있는] 사람 = someone [(on/with whom) there IS a pen]. "펜이 있다" just says there is a pen, and -는 connects this fact with 사람.

Hello^^ First, I'm afraid there is no meaning 'to have' in the verb'~있다'. it is more like 'There is' or saying something's status. For example, 신은 있다. There is GOD. 기회가 아직 있다. still, there is a chance. (we are in a situation, and the situation is still we have a chance) so, 펜이 있어? ( Is there a pen?)-> As you know, when people borrow a pen from others, you can say in this way. So it may make people confuse, but there is no meaning 'to have' in ~있다. 가지고/가졌어 is another form of ~가지다. and 가지고 있다 is 가지다+있다. not 가지+고+있다 so 가지고 있다's meaning is 'it is in status, having something' for example, 재호가 something을 가지고 있다.-> there is 재호 who is in status, having something 칼 가지고 있어?-> are you in a situation, which you have a knife?-> are you having a knife?-> Do you have a knife? (in specific situations) Thanks^^ If you have other questions, plz leave comments p.s and ~있다 is usually translated to 'be' verb, which has very profound meaning some point of views. For example, we usually translate There is Bob->밥이 있다. ^^;; I do want to explain more about this but maybe next time when I study more about this I will leave a comment

Thank you both for an explanation! I think I understand it better now. (I don’t want to give the ‚best answer’ cause I appreciate your help equally and I think that wouldn’t be fair hah)