This is an idiomatic expression. He's not really placing his hand upon a body part - in this case, his heart. That would involve cutting a hole into his chest which I imagine is quite dangerous.
However, anyone confused about the rules should check out these articles:
- Using le, la, les with body parts and clothing (definite articles)
- Using mon, ma, mes, etc with parts of the body (possessive adjectives)
Duolingo's grammar tips & notes for the Medical skill do attempt to explain the rules to some extent, but that is much later in the course (quite close to the end).
I don't think it is so precise. You really have to get used to dropping the sound of the last letter of many words which makes alot of them sound the same, yes context and all, but you know what I mean. So, not precise to me, and awfully wordy to say simple things, imo. Nonetheless, I love the French language!
Here it seems we have an exception to the rule that we don't usually use possessive pronouns with body parts. It is "j'ai une douleur dans le (instead of mon) cou" But here we have "il a mis sa main sur son (instead of le) coeur. Is this to avoid a double use of the definite article?
Wow. That makes years of mystery, solved. So all I was missing was a comma, huh?
"Je veux crever, la main sur le cœur"
Jeez. Finally makes sense. Thanks. :')
Je veux de l'amour, de la joie, de la bonne humeur,
Ce n'est pas votre argent qui fera mon bonheur,
Moi, j'veux crever, la main sur le cœur."
(...Well maybe that would still be confusing, implying you actually want to die, ergh, whatever).
Je suis de votre avis que cette expression française est un peu bizzare "sa main sur son coeur". Il me semble naturel de dire: "Il a mis la main sur le coeur". Du côté de genre qui exprime les différences non bilogiques, à la lumière de cette phrase, il ya trois options pour une langue: -de ne l'utilser pas -de se referer à l'objet (main, coeur) -de se refere au sujet possesseur (Pierre, Mathilde, lui, elle, eux, des patients,...etc) Le second choix c'est celui du français, le troisième c'est celui de l'anglais, de l'arabe et d'autres langues. Il me parait que le dernier soit le plus intelligent par ce que on sait toujours le genre de la main, du coeur, mais on n'est pas joujours certain du genre du possesseur.
An interesting point. But there are three differences between French and English that lead to the difference in the choice of what modifier to use before hand and heart in this example. English does not assign a gender to every noun, so we have no need to indicate that in a sentence; English does not need to have a definite article before every noun, in this case it definitely calls for a pronoun, "its' is the only other choice; and pronouns in English do have a gender that references the subject of the phrase. There is no one for one translation for the pronouns he/she or his/her from English to French.
For me it is internalizing these kind of differences that makes learning a language interesting.