diff --git a/wani.py b/wani.py
index 61f477b..3694b21 100644
--- a/wani.py
+++ b/wani.py
@@ -813,6 +813,7 @@ class Writer:
         self.without_rep = args.without_rep
         self.output_file = args.output
         self.multiple_output = args.multiple_output
+        self.sort_by = int(args.sort_by)
 
     def header(self):
         cols = ["Lemma"]
@@ -847,11 +848,28 @@ class Writer:
                 cols += [""] #not yet implemented...
 
         return cols
+    
+    def sorted_rows(self, rows):
+        if self.sort_by < 0 or len(rows) < 2:
+            return rows
+
+        if len(rows[0]) <= self.sort_by:
+            print("Cannot sort by column #{}: Not enough columns!".format(len(rows[0])), file=sys.stderr)
+            return rows
+        
+        try:
+            int(rows[0][self.sort_by])
+            key=lambda row: int(row[self.sort_by])
+        except ValueError:
+            key=lambda row: row[self.sort_by].lower()
+
+        return sorted(rows, key=key)
 
     def write_header(self, file_handler):
         file_handler.write(", ".join(self.header()) + "\n")
 
     def write_out_worker(self, file_handler, matches, structure_id, components, colocation_ids):
+        rows = []
         for m, reason, cid in matches:
             to_write = []
 
@@ -874,8 +892,10 @@ class Writer:
                     to_write.append(colocation_ids.num(cid))
                     colocation_ids.set_written(cid)
 
-            file_handler.write(", ".join(to_write) + "\n")
+            rows.append(to_write)
 
+        rows = self.sorted_rows(rows)
+        file_handler.write("\n".join([", ".join(row) for row in rows]) + "\n")
         file_handler.flush()
 
     def write_out(self, matches, structures, colocation_ids):
@@ -901,7 +921,8 @@ class Writer:
                 self.write_header(fp)
 
             sid_matches = matches[s.id]
-            self.write_out_worker(fp, sid_matches, s.id, s.components, colocation_ids)
+            if len(sid_matches) > 0:
+                self.write_out_worker(fp, sid_matches, s.id, s.components, colocation_ids)
 
             if self.multiple_output:
                 fp_close(fp)
@@ -1029,6 +1050,7 @@ if __name__ == '__main__':
     parser.add_argument('--verbose', help='Enable verbose output to stderr', choices=["warning", "info", "debug"], default="info")
     parser.add_argument('--count-files', help="Count files: more verbose output", action='store_true')
     parser.add_argument('--multiple-output', help='Generate one output for each syntactic structure', action='store_true')
+    parser.add_argument('--sort-by', help="Sort by a this column (index)", type=int, default=-1)
 
     parser.add_argument('--pc-tag', help='Tag for separators, usually pc or c', default="pc")
     parser.add_argument('--parallel', help='Run in multiple processes, should speed things up')