"-am" meaning in Esperanto

{
  "etymology_links": [
    [
      "kiam",
      "kiam"
    ],
    [
      "tiam",
      "tiam"
    ],
    [
      "iam",
      "iam"
    ],
    [
      "ĉiam",
      "ĉiam"
    ],
    [
      "neniam",
      "neniam"
    ],
    [
      "-a",
      "-a"
    ],
    [
      "-n",
      "-n"
    ]
  ],
  "etymology_text": "Initially, the correlatives for time ended with -an instead of -am: kian, tian, ian, ĉian, nenian instead of the modern kiam, tiam, iam, ĉiam, neniam. Zamenhof left a one-year period (from Esperanto's creation in 1887 to 1888) during which changes to Esperanto could be proposed. After that year, the only change that was made was changing the time correlatives from -an to -am due to the risk of confusion with correlatives ending with -a + the accusative ending -n. The forms with -an are no longer used, but they can be found in a few older texts from that one-year period. This is the only reform proposal that has ever been successfully implemented into Esperanto.",
  "head_templates": [
    {
      "args": {
        "1": "eo",
        "2": "suffix"
      },
      "expansion": "-am",
      "name": "head"
    }
  ],
  "hyphenation": [
    "-am"
  ],
  "hyphenations": [
    {
      "parts": [
        "",
        "am"
      ]
    }
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Esperanto entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 12 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "derived": [
        {
          "english": "always",
          "translation": "always",
          "word": "ĉiam"
        },
        {
          "english": "sometime",
          "translation": "sometime",
          "word": "iam"
        },
        {
          "english": "when",
          "translation": "when",
          "word": "kiam"
        },
        {
          "english": "never",
          "translation": "never",
          "word": "neniam"
        },
        {
          "english": "then",
          "translation": "then",
          "word": "tiam"
        },
        {
          "english": "(at) another time, sometime else",
          "sense": "nonce",
          "translation": "(at) another time, sometime else",
          "word": "aliam"
        }
      ],
      "glosses": [
        "suffix for correlatives of time"
      ],
      "id": "en--am-eo-suffix-zBtn1tVZ",
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/am/"
    },
    {
      "rhymes": "-am"
    }
  ],
  "word": "-am"
}

{
  "derived": [
    {
      "english": "always",
      "translation": "always",
      "word": "ĉiam"
    },
    {
      "english": "sometime",
      "translation": "sometime",
      "word": "iam"
    },
    {
      "english": "when",
      "translation": "when",
      "word": "kiam"
    },
    {
      "english": "never",
      "translation": "never",
      "word": "neniam"
    },
    {
      "english": "(at) another time, sometime else",
      "sense": "nonce",
      "translation": "(at) another time, sometime else",
      "word": "aliam"
    },
    {
      "english": "then",
      "translation": "then",
      "word": "tiam"
    }
  ],
  "etymology_links": [
    [
      "kiam",
      "kiam"
    ],
    [
      "tiam",
      "tiam"
    ],
    [
      "iam",
      "iam"
    ],
    [
      "ĉiam",
      "ĉiam"
    ],
    [
      "neniam",
      "neniam"
    ],
    [
      "-a",
      "-a"
    ],
    [
      "-n",
      "-n"
    ]
  ],
  "etymology_text": "Initially, the correlatives for time ended with -an instead of -am: kian, tian, ian, ĉian, nenian instead of the modern kiam, tiam, iam, ĉiam, neniam. Zamenhof left a one-year period (from Esperanto's creation in 1887 to 1888) during which changes to Esperanto could be proposed. After that year, the only change that was made was changing the time correlatives from -an to -am due to the risk of confusion with correlatives ending with -a + the accusative ending -n. The forms with -an are no longer used, but they can be found in a few older texts from that one-year period. This is the only reform proposal that has ever been successfully implemented into Esperanto.",
  "head_templates": [
    {
      "args": {
        "1": "eo",
        "2": "suffix"
      },
      "expansion": "-am",
      "name": "head"
    }
  ],
  "hyphenation": [
    "-am"
  ],
  "hyphenations": [
    {
      "parts": [
        "",
        "am"
      ]
    }
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Esperanto 1-syllable words",
        "Esperanto entries with incorrect language header",
        "Esperanto lemmas",
        "Esperanto suffixes",
        "Esperanto terms with IPA pronunciation",
        "Esperanto terms with audio pronunciation",
        "Pages with 12 entries",
        "Pages with entries",
        "Rhymes:Esperanto/am",
        "Rhymes:Esperanto/am/1 syllable"
      ],
      "glosses": [
        "suffix for correlatives of time"
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/am/"
    },
    {
      "rhymes": "-am"
    }
  ],
  "word": "-am"
}