A thousand or a thousand? Such expressions raise those endless doubts we have about our language. How many times have we come across situations like this:
I paid for this check the amount of one thousand nine hundred and ninety reais.
Doing a survey in order to find out what bank managers think about this issue, they will possibly say that it is a recurrent and normal situation, since the cardinal numeral "one", once expressed with the unit of thousands, is used to prevent fraud occur.
However, we must assert that before the grammatical postulates such a placement is considered inadequate, a since only from two thousand, and so on, is it necessary to use the aforementioned cardinal. So we have “two thousand, three thousand, four thousand”, and so on.
Therefore, the appropriate procedure for this situation (writing checks) is to use the sign (=) before starting to fill in the amount in words.
Believe that, in certain situations, there was still the use of the “h” to express the desired amount. "Hmm"! Certainly our interjection “hum” would send the numeral “hum”, which does not exist.
Well, as already said, the truth is that before the unit of thousands, except from two thousand onwards, the use of the numeral “one” is not recommended. The same prevails for the dates, in which the inadequacy is recurrent. So, let's see:
1998 – One thousand nine hundred and ninety-eight.
1847 – One thousand eight hundred and forty-seven.
By Vânia Duarte
Graduated in Letters
Source: Brazil School - https://brasilescola.uol.com.br/gramatica/um-mil-ou-mil.htm