Ndtyjky

var connectives = {

    das: true,

    da: true,

    dos: true,

    do: true,

    de: true,

    e: true

};



function capitalize(str) {

    return str

        .split(" ")

        .map(function(word) {

            return !connectives[word.toLowerCase()]

                ? word.charAt(0).toUpperCase() + word.slice(1).toLowerCase()

                : word.toLowerCase();

        })

        .join(" ");

};



$(".capitalize").keyup(function() {

    var cursorStart = this.selectionStart;

    var cursorEnd = this.selectionEnd;

    var capitalizedString = capitalize($(this).val());



    $(this).val(capitalizedString);

    this.setSelectionRange(cursorStart, cursorEnd);

});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<label>Nome: </label>

<input type="text" id="nome" name="nome" class="form-control input-sm capitalize">

function format(string, noCapList=) {

  const words = string.toLowerCase().split(' ');

  return words.map((word) => {

    if(!word.length || noCapList.includes(word)) {

      return word;

    } else {

      return word[0].toUpperCase() + word.slice(1);

    }

  }).join(' ');

}



const input = document.querySelector('input');

input.addEventListener('keyup', () => {

  input.value = format(input.value, ["das", "da", "dos", "do", "de", "e"]);

});

<input/>

function ucfirst (str) {

    //  discuss at: http://locutus.io/php/ucfirst/

    str += '';

    var f = str.charAt(0).toUpperCase();

    return f + str.substr(1);

}



var not_capitalize = ['de', 'da', 'do', 'das', 'dos', 'e'];

$.fn.maskOwnName = function(pos) {

    $(this).keypress(function(e){

        if(e.altKey || e.ctrlKey)

            return;

        var new_char = String.fromCharCode(e.which).toLowerCase();

        

        if(/[a-zà-ú., ]/.test(new_char) || e.keyCode == 8){

            var start = this.selectionStart, end = this.selectionEnd;

        

        if(e.keyCode == 8){

            if(start == end)

                start--;



            new_char = '';

        }

        

        var new_value = [this.value.slice(0, start), new_char, this.value.slice(end)].join('');

        var maxlength = this.getAttribute('maxlength');

        var words = new_value.split(' ');

        start += new_char.length;

        end = start;



        if(maxlength === null || new_value.length <= maxlength)

            e.preventDefault();

        else

            return;



        for (var i = 0; i < words.length; i++){

            words[i] = words[i].toLowerCase();



            if(not_capitalize.indexOf(words[i]) == -1)

                words[i] = ucfirst(words[i]);

        }



        this.value = words.join(' ');

        this.setSelectionRange(start, end);

    }

});



$.fn.maskLowerName = function(pos) {

  $(this).css('text-transform', 'lowercase').bind('blur change', function(){

      this.value = this.value.toLowerCase();

  });

};



$.fn.maskUpperName = function(pos) {

  $(this).css('text-transform', 'uppercase').bind('blur change', function(){

      this.value = this.value.toUpperCase();

  });

};



};



$('.capitalize').maskOwnName();

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<label>Nome: </label>

<input type="text" id="nome" name="nome" class="form-control input-sm capitalize">