public IHttpActionResult PostWordLearned(WordModel word)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            try
            {
               var id = _service.CreateWord(word);
                return CreatedAtRoute("DefaultApi", new { id = id }, id);
            }
            catch (DbUpdateException)
            {
                return InternalServerError();
            }
        }
        public IHttpActionResult PutWordLearned(WordModel wordLearned)
        {
            try
            {
                if (!ModelState.IsValid)
                {
                    return BadRequest(ModelState);
                }

                _service.UpdateWord(wordLearned);

                return StatusCode(HttpStatusCode.OK);
            }
            catch (Exception)
            {
                return InternalServerError();
            }
        }