Translation:He is thinning himself
@vtopphol has good explanation. reflexive -ji- shows he is doing it to himself (ie dieting) instead of disease is causing it. A better contextual translation is 'he is on a diet'.
Rudolf, yes, it's weird. I would say something more like "he is losing weight" or "he is getting thinner".
I agree with you. The problem is that in Swahili they distinguish more clearly between "becoming thinner" and "causing to get thinner". Anajikondesha would mean literally "He causes himself to loose weight". I don't know any shorter way of saying this, and at the same time distinguish it from loosing weight because of, for instance, a disease.
Well, for most cases this would be correct, but it doesn't cover all possibilities. There are other reasons than dieting. He could be on a hunger strike. Then losing weight is self caused, but I don't think you would say dieting in that case.
I might be wrong, since I'm not a native speaker in English nor Swahili. But I don't think I am wrong.
You're right - of course you wouldn't describe hunger strike as dieting. Swahili is elegant enough to encapsulate both benign and destructive forms of 'thinning oneself' (which isn't a phrase in English) in one word. English phrases are nuanced according to the intent behind the slimming project! By 'he's on a diet I'm just suggesting the one used in perhaps 99.9% of cases. We also very commonly say "he's trying to lose weight" but that seemed a confusing suggestion when -jaribu is not part of the Swahili construction.
Rudolph, I agree it sounds weird. In English I would say it as "he is losing weight" or "he is getting thinner."
He is slimming would be correct (British) English according to the Oxford Dictionary of English:
verb (slims, slimming, slimmed) [no object] (British) make oneself thinner by dieting and sometimes exercising: if he's overweight, he should slim | (as noun slimming) : an aid to slimming.
And this should not be translated as 'She/He is on a diet" since there are other ways to loose (and keep) weight. Like exercising or doing hard physical labour.
I am afraid the lessons need a native English speaker versed in both US and UK English to correct some of these answers.