title: Understanding multi-fields to analyze the text once per language
body: <p>I'm implementing an analyzer for my ES, and I'm trying to understand the multi-fields to analyze the text once per language, as my document can have multiple languages.</p>
  
  <pre><code>"properties": {
      "body" : {
          "type": "string",
          "fields": {
              "fr": {
                  "type": "string",
                  "analyzer": "french"
              },
              "en": {
                  "type": "string",
                  "analyzer": "english"
              },
              "es": {
                  "type": "string",
                  "analyzer": "spanish"
              },
              "de": {
                  "type": "string",
                  "analyzer": "german"
              },
              "pt": {
                  "type": "string",
                  "analyzer": "portuguese"
              },
              "nl": {
                  "type": "string",
                  "analyzer": "dutch"
              },
              "dk": {
                  "type": "string",
                  "analyzer": "danish"
  }}}}
  </code></pre>
  
  <p>How does this really work? There's no further info in <a href="https://www.elastic.co/guide/en/elasticsearch/guide/current/mixed-lang-fields.html#_analyze_multiple_times" rel="nofollow">ES docs</a>.</p>
  
  <p>For example, if If I try to index the string <code>Hello, my car is red</code>, the analyzers examines it in all languages until it detects its in english, so it creates the inverted index using <code>english</code> analyzer?</p>
  
  <p>Thanks in advance.</p>