Kegan, I wonder if we are talking about the same definitions. The term "disjuntive" implies that goes in opposition or against something or is isolated. whether we talk about a preposition or a pronoun. In the case of a preposition: They are tired but happy In this case "but" separates the adjective "happy" from the rest of the sentence and give a contrary idea, making "but" a disjunctive preposition. In the case of a pronoun, it must be against something or separated in some way, for example: The guys are drinking coffe, but me, I am drinking a beer. In this case you can say that "me" is a disjunctive objective pronoun, since it is isolated and performing a action contrary the other subjects of the sentence. As for the sentence you set as an example "I am thinking about you". I am not sure if you understand the concept of "indirect object" (dative) and "direct object" (accusative), since this sentence is follows the "S-V-O" pattern. I don't think that the use of "about" might be confusing you, so, I will let you read some definitions before saying anything else. About your opinion on the fact that "in Romance languages, a pronoun after a preposition is disjunctive" I have to disagree with you. It is true that it can happen, but it is not the rule... it is actually not even the most common pattern. Discutimos sobre ella We talked about her (Just using a sentence to show the same preposition you used before), again, in this sentence there is no contraposition of any kind neither is there an isolation of any subject, thus, there can't be a disjunctive pronoun. I don't really understand you phrase "English USED to have cases"... like it did not today. Could you tell me what kind of material (assuming you have read books on the subject) provided you with this questions about grammar? And, just to answer your question... a pronoun can be both indirect object and disjunctive, for example: The teacher bought books for all the kids but for him. In this case, "him" is isolated from the other kids and he is also the indirect object (dative) of the sentence, since "the books" are the direct object (accusative). Cheers, Mario