title: Lemmatization not working on words starting with capitol letters
body: <p>I am working on a project that uses StanfordNLP. One of the function in the project it to extract all nouns from a piece of text and lemmatize each noun. I am extracting the nouns using the below code</p>
  
  <pre><code>        Properties props = new Properties();
          props.setProperty("annotators", "tokenize, ssplit, pos, lemma, parse, natlog, openie");
          StanfordCoreNLP pipeline = new StanfordCoreNLP(props);
  
  
          Annotation document = new Annotation(text);
  
          pipeline.annotate(document);         
  
          List&lt;CoreMap&gt; sentences = document.get(SentencesAnnotation.class);
  
          for(CoreMap sentence: sentences) {
  
            SemanticGraph dependencies = sentence.get(BasicDependenciesAnnotation.class);
            List&lt;String&gt; Nouns = Extractnouns(dependencies.typedDependencies(), sentence); 
          }
  
       private List&lt;String&gt; Extractnouns(Collection&lt;TypedDependency&gt; tdl, CoreMap sentence) { 
       List&lt;String&gt; concepts=new ArrayList&lt;String&gt;();
       for (TypedDependency td : tdl) 
              {
  
                  String govlemma = td.gov().lemma(); 
                  String deplemma = td.dep().lemma(); 
                  String deptag=td.dep().tag();
                  String govtag=td.gov().tag();
                  if(deptag!=null &amp;&amp; deptag.contains("NN") )
                  {
                       concepts.add(deplemma);
                   }
                  if(govtag!=null &amp;&amp; govtag.contains("NN") )
                  {
                       concepts.add(govlemma);
                   }
               }
           return concepts;
  </code></pre>
  
  <p>}</p>
  
  <p>It is working as expected but for some words the lemmatization is not working. I observed that some of the nouns that come as the first word in a sentence have this problem. Example: "Protons and electrons both carry an electrical charge." Here the word "Protons" is not getting converted to "proton" on applying lemma. Same with with some other nouns too. </p>
  
  <p>Could you please tell me a solution for this problem? </p>