Hello 🌺 1. They already get social welfare. 2. They already get social welfare and want additional benefits. (=more, better benefits.) I'm not native, however I did my best to clarify the difference between the two sentences. ☺️

I'm not sure what the first sentence means or what you intend it to mean. The second sentence is correct and very clear. Part of the problem is that the phrase "take up" is not really appropriate in this sentence. You take up a hobby, take up space or take up time. You could take up social welfare as a political cause, for example, but we would indicate that somehow in the sentence, for example: "In the next election they will take up social welfare as a first priority". In that case you would want to drop the possessive pronoun, because it indicates that they are "taking up" social welfare generally, as opposed to campaigning for their own individual social welfare. If you mean they will begin taking their social welfare, or start taking social welfare whereas before they did not take social welfare, then you would write that differently: "They began taking social welfare after being laid off by Twitter". Hope that helps.