In Thai, 'ซึ่ง (sûeng)' is commonly used as a relative pronoun, similar to the English 'which' or 'who'. It is usually used to introduce information about something or someone already mentioned in a sentence, acting as a connector between the main clause and a subordinate clause. Interestingly, 'ซึ่ง' does not distinguish between animate and inanimate or between people and objects, unlike English relative pronouns.