I understand that -tagatte comes from -tagar.u, but I have a problem understanding iru n(o) desu ga. i.e. Watashi no kanai wa mizu o (why o) nomitagatte iru n desu ga (my wife wants to drink water). Has this the same meaning as (in the first person) mizu ga (why ga) nomitai n desu ga? domo arigato Luc Vileyn

I'll try and help: The "iru n(o) desu ga" is a structure indicating continuous action. Your wife IS wanting to drink water. The -te form of a verb + iru indicates continuous action and " n desu ga " is a sentence softener. The use of "o" vs "ga" is a bit more complicated. In the first sentence, "nomitagatte iru" functions as a verb. The object marker "o" is therefore used to indicate the " wanting to drink" is being done to the water by your wife. Conversely, in the second sentence, "nomitai" is actually an auxiliary adjective, and is qualifying the water. Hence, the water is the topic/subject and is followed by "ga". Yep, the two sentences have the same meaning, but third person and first person respectively. Tagaru is added to verb stems to indicate other people's wishes. It's actually a combination of the -tai ending (for wanting) and the auxiliary verb "garu" meaning to "feel". Hope that helps. Sorry I'm not better at Japanese =S

Wakarimashita. Domo arigoto gozaimashita!