It's correct as far as it goes: it's a complete and correct noun phrase. It's not a complete sentence, however, because it's missing (at least) a verb.
Not in English, no. Perhaps you mean 'disingenuous' which is a word which means not candid or sincere.
Antonyms for sincere include:deceitfuldishonestdisingenuousinsincerelyingtrickytwo-faceduntrustworthy
The correct spelling is 'sincere'.
The way you have it spelled in your question is as good as any - it's not really a word. Sincere is a word who's comparative and superlative are : more sincere, most sincere.
No one believed that he sincerely cared about his job.I sincerely considered every consequence of my actions.
"With sincere appreciation" is the correct phrase. It indicates that the appreciation is accompanied by sincerity.
הכרת תודה (pronounced hah-kah-RAHT toh-DAH).
"Sentido" in English can be translated as "meaning" or "sense."
You may say 'seijitsu.'
Not in English, no. Perhaps you mean 'disingenuous' which is a word which means not candid or sincere.
I'm very sorry , but this makes no sense to me whatsoever , but if you meant Author Andrew Carnegie, he passed away many years ago.
An acknowledgement should be brief and to the point. It should express gratitude and recognition without being overly long or detailed. Aim for a few sentences that convey sincere appreciation.
The comparative degree of sincere is more sincere.
A sincere person is always respected for his sincerity. This is the sincere approach to make a sentence with the word 'sincere'.he was sincere in his efforts to please
The superlative degree of word sincere can be most sincere ,or sincerest according to its use in the sentence.
Antonyms for sincere include:deceitfuldishonestdisingenuousinsincerelyingtrickytwo-faceduntrustworthy
I gave a sincere apology to my mother.