转换IEnumerable< string>字典

在将bool distinct添加到方法Splitter并检查distinct is true是否代码破裂后。现在的查询不是字典，而是IEnumerable<string>，而应该是Dictionary<string, int>。如何解决这个问题?

错误:

不能隐式转换类型"System.Collections.Generic"。到"System.Collections.Generic.Dictionary"。存在显式转换(您是否缺少强制类型转换?)

和代码:

private Dictionary<string, int> Splitter(string[] file, bool distinct)
{
    var query = file
        .SelectMany(i => File.ReadLines(i)
        .SelectMany(line => line.Split(new[] {' '}, StringSplitOptions.RemoveEmptyEntries))
        .AsParallel()
        .Select(word => word.ToLower())
        .Where(word => !StopWords.Contains(word))
        .Where(word => !StopWordsPl.Contains(word))
        .Where(word => !PopulatNetworkWords.Contains(word))
        .Where(word => !word.All(char.IsDigit)));
        if (distinct)
        {
        query = query.Distinct();
        }
       query.GroupBy(word => word)
            .ToDictionary(g => g.Key, g => g.Count());
       return query;
}

return query.GroupBy(word => word)
            .ToDictionary(g => g.Key, g => g.Count());