"She doesn't tell him."
Translation:Sie sagt es ihm nicht.
That's true, but there are a couple of examples where the German needs an object that can be left out in English. This is one of those. (Even in the situations where you could colloquially leave it out in the German, it would sound sloppy for anyone who's still learning the language).
What triggers the necessity of adding the direct object? I mean, I can say "Ich helfe ihm nicht." but I wouldn't say "Ich helfe es ihm nicht."
Would you happen to have a conceptual answer or is this something particular to German that one would need to remember with certain cases?
Good question (mine also).
I understand that "helfen" is a verb which requires only an indirect object (Dative Case) and no direct object - that's why "es" or an direct object doesn't belong to the second sentence you gave.
But I am not sure why in our case here, regarding the verb "sagen".
I made a little research and have found that this verb works like this: "jemandem etwas sagen" (this is the Infinitiv - to tell something to somebody), in which jemandem is Dative and etwas is Accusative. Source: click here
There is a rule that says that if you have two personal pronouns, one accusative and one dative, then the accusative pronoun comes first. In this case, 'es' is accusative and 'ihm' is dative, so 'Sie sagt es ihm nicht." Under other circumstances, it's dative before accusative, so you can say for example, 'Sie sagt ihm die Wahrheit.'
Some verbs which require/call for the dative case don't require an object like "es". For example, "helfen": jemandem helfen - to help somebody.
But, just like you suggested, in this case the way the verb works in German is: "jemandem etwas sagen", where "etwas" is in the accusative case. Or one can also just say something, "etwas sagen", without saying it to somebody.
Not really a change in the meaning of "nothing". So, in this example, it could be translated as "Sie lacht und sagt ihm nichts." Otherwise it could end as "Sie lacht, sagt ihm es nicht, und sprecht von etwas anders."
By the way, I forgot to mention that "nothing" is the translation of "nichts" (probably you already know it).
Do all dative pronouns just mean to add a 'to' before the original pronoun? Like mir is to me or dir means to you and so on? Can this be a general rule of thumb? Or that objects that are being performed an action to will be dative and the object on which the action is being performed will be accusative? E.g. She gave Sarah the money. So she is nominative, Sarah is dative and money is accusative. Am I right?
M4Yj6 - Two mistakes:
1) 'ihn' is accustive, which is not what is needed here. Due to the specific use of the verb 'sage' in this case (to say something to someone), you need the dative 'ihm', which I personally interpret as 'to him' or sometimes 'for him' but not just the accusative 'him';
2) You also needed to include 'es'. It is just the way it is: I also struggled with 'es' here, which may not be required in English but apparently is required in German. Best to just learn it by heart.
Just like az_p said above, this is one of those sentences in German which needs an extra object even if it doesn't make any sense in English.
German "it" is different from english "it". Mostly because, germans use it in sentences for no reason at all.
It acts as a filler object.
For a longer version, please read this article: https://yourdailygerman.com/word-of-the-day-es/