What exactly is the rule that turns the "vet" to a "bet" in the word "רטובים"?
No rule. Bet can also be V. you can't know without Nikud. only to remember the words.
This is also true for Kaf (Haf),Shin (Sin) and Pey (Fey)
I suspect its a rule that has something to do with the letters that get affected (plus the place in the syllable and the surrounding vowels ). I seem to remember that there IS a rule, its just that I last studied Hebrew so long ago that I can't dredge it up.
Specifically to this sentence, there is a rule (though there may be some exceptions) that when an 'O' sound becomes 'U', the following letter gets "דגש חזק". Examples -
צהוב => צהובים (tsahov => tsehubim)
ארוך => ארוכים (arokh=> arukim)
דוב => דובים (dov => dubim)
Also, most Hebrew speakers would use the form "ratuv" => "retuvim" which is grammatically correct as well.
As far as i know, 'Pey' is always 'p' at the beginning of a word and 'f' at the ending, and the similar thing is with 'Kaf' and 'Bet'. But i am neither a specialist nor a native speaker, so i don't know exactly...
There's a rule, though what makes this complicated is that spoken Modern Hebrew has drifted away from the rule, so you tend to sound a bit like you're trying too hard when you follow all of the rules, almost like if you overenunciate in English and people give you funny looks. The rules here are largely used for official speech, like on news broadcasts.
Because "מסלול" means "path" or "route", not "road". It's just a different word with a slightly different meaning.
"All courses are wet" is not a correct answer, right? The android app gives this as the only option.
Why not? Not courses as classes/lessons, but in the meaning of a path (like a golf course).
'Courses' is not used by itself in English to mean a path. Nobody ever 'walks along a course'.
Oh, you might be right. I think both are OK, except one is more general than the other ("All courses" as in all the courses that exist). It's like the difference between "All men are happy" and "all the men are happy".
But I'm not a native speaker.
So should we translate 'כל ה' like 'all' or 'all the'? Because the application accepts both these variants, though it makes difference. Or it doesn't?
There is a rule about letters following י ה ו א and whether they get a dagesh or not.
There's a line in a song by Sarit Hadad "ליבי רטוב". Does this make any sense? (Apart from the fact that it rhymes to the previous line?) http://m.shironet.mako.co.il/artist?type=lyrics&lang=1&prfid=1015&wrkid=18225