diff --git a/Makefile b/Makefile
index 15704319..3b4d6654 100644
--- a/Makefile
+++ b/Makefile
@@ -116,7 +116,7 @@ progress:
 
 .PHONY: spellcheck
 spellcheck:
-	$(PYTHON) scripts/check_spelling.py $(filter-out $@, $(MAKECMDGOALS))
+	$(PYTHON) scripts/check_spelling.py --print-errors $(filter-out $@, $(MAKECMDGOALS))
 
 .PHONY: lint
 lint:
diff --git a/scripts/check_spelling.py b/scripts/check_spelling.py
index 3b55c155..b532f88e 100644
--- a/scripts/check_spelling.py
+++ b/scripts/check_spelling.py
@@ -1,9 +1,17 @@
 """
 Script to check the spelling of one, many or all .po files based
 on the custom dictionaries under the 'dictionaries/' directory.
+
+Gives the option to print the detected errors and add new entries to the dictionary file.
+
+Display information about usage with `python scripts/check_spelling.py --help`
 """
 
+import argparse
+import contextlib
+import functools
 import os
+import multiprocessing
 from pathlib import Path
 import sys
 import tempfile
@@ -11,22 +19,92 @@
 import pospell
 
 
-def check_spell(po_files=None):
+def main():
+    parser = create_parser()
+    args = parser.parse_args()
+
+    errors = check_spell(args.po_files)
+
+    if args.print_errors:
+        print_errors(errors)
+
+    if args.write_entries:
+        write_new_entries({e[-1] for e in errors})
+
+    sys.exit(0 if len(errors) == 0 else -1)
+
+
+def create_parser():
     """
-    Check spell in the given list of po_files and log the spell errors details.
+    Creates and configures the command line argument parser.
+
+    returns:
+        - argparse.ArgumentParser: the argument parser containing the passed arguments and flags.
+    """
+    parser = argparse.ArgumentParser(
+        usage="python check_spelling.py [options]",
+        description="spell-check translated .po files and add new entries to the dictionary if needed.",
+    )
+
+    parser.add_argument(
+        "-p",
+        "--print-errors",
+        action="store_true",
+        dest="print_errors",
+        help="print the detected errors of the spell-check",
+    )
+    parser.add_argument(
+        "-w",
+        "--write-entries",
+        action="store_true",
+        dest="write_entries",
+        help="write the new detected entries in the dictionary file",
+    )
+    parser.add_argument(
+        "-f",
+        "--po-files",
+        dest="po_files",
+        nargs="*",
+        default=list(),
+        help="list of .po files to spell-check, if not given checks all po files",
+    )
+
+    return parser
 
-    If no po_files are given, check spell in all files.
+
+def check_spell(po_files):
+    """
+    Check spell in the given list of po_files.
 
     args:
         po_files: list of po_files paths.
 
     returns:
-        - int: spell errors count.
+        - list: list of tuples containing detected errors.
+    """
+    entries = read_dictionary_entries()
+
+    with write_entries_to_tmp_file(entries) as named_tmp_file:
 
+        # Run pospell either against all files or the files given on the command line
+        if len(po_files) == 0:
+            po_files = Path(".").glob("*/*.po")
+
+        detected_errors = detect_errors(po_files, named_tmp_file.name)
+    return detected_errors
+
+
+def read_dictionary_entries():
+    """
+    Read the entries in the dictionary files under `dictionaries` directory.
+
+    returns:
+        - set: a set of string entries
     """
-    # Read custom dictionaries
     entries = set()
-    for filename in Path("dictionaries").glob("*.txt"):
+    dictionaries = Path("dictionaries").glob("*.txt")
+
+    for filename in dictionaries:
         with open(filename, "r") as f:
             entries.update(
                 stripped_line
@@ -34,7 +112,20 @@ def check_spell(po_files=None):
                 if stripped_line
             )
 
-    # Write merged dictionary file
+    return entries
+
+
+@contextlib.contextmanager
+def write_entries_to_tmp_file(entries):
+    """
+    Write the given entries to a named temporary file and yield the file.
+
+    args:
+        entries: a set of entries (strings) to write to the temporary file.
+
+    returns:
+        - tempfile.NamedTemporaryFile: the temporary file with the given entries.
+    """
     with tempfile.NamedTemporaryFile(suffix="_merged_dict.txt") as named_tmp_file:
         for e in entries:
             named_tmp_file.write(f"{e}\n".encode())
@@ -44,17 +135,97 @@ def check_spell(po_files=None):
 
         named_tmp_file.seek(0)
 
-        # Run pospell either against all files or the file given on the command line
-        if not po_files:
-            po_files = Path(".").glob("*/*.po")
+        yield named_tmp_file
+
+
+# Clone of pospell.spell_check tailored to current needs.
+# source: https://git.afpy.org/AFPy/pospell/src/branch/main/pospell.py
+def detect_errors(po_files, personal_dict):
+    """
+    Check for spelling mistakes in the given po_files.
+
+    args:
+        po_files: list of strings or Path objects pointing to po files.
+        personal_dict: name of file containing dictionary entries.
+
+    returns:
+        - list: a list of tuples with the detected errors
+    """
+    # Pool.__exit__ calls terminate() instead of close(), we need the latter,
+    # which ensures the processes' atexit handlers execute fully, which in
+    # turn lets coverage write the sub-processes' coverage information
+    jobs = os.cpu_count()
+    pool = multiprocessing.Pool(jobs)
 
-        detected_errors = pospell.spell_check(
-            po_files, personal_dict=named_tmp_file.name, language="el_GR"
+    try:
+        input_lines = pospell.flatten(
+            pool.map(
+                functools.partial(pospell.po_to_text, drop_capitalized=False),
+                po_files,
+            )
         )
-    return detected_errors
+
+        if not input_lines:
+            return []
+
+        # Distribute input lines across workers
+        lines_per_job = (len(input_lines) + jobs - 1) // jobs
+        chunked_inputs = [
+            input_lines[i : i + lines_per_job]
+            for i in range(0, len(input_lines), lines_per_job)
+        ]
+        errors = pospell.flatten(
+            pool.map(
+                functools.partial(pospell.run_hunspell, "el_GR", personal_dict),
+                chunked_inputs,
+            )
+        )
+    finally:
+        pool.close()
+        pool.join()
+
+    return errors
+
+
+def print_errors(errors):
+    """
+    Print the given errors with the following format:
+    filename:linenumber:word
+
+    args:
+        errors: list of tuples with detected errors.
+    """
+    if len(errors) > 0:
+        print("\nDetected errors:")
+
+    for error in errors:
+        print("\t" + ":".join(map(str, error)))
+
+
+def write_new_entries(new_entries):
+    """
+    Write the given entries to the dictionary file respecting the
+    alphabetical sorting.
+
+    args:
+        new_entries: set of entries (strings) to write to the dictionary file.
+    """
+    entries = read_dictionary_entries()
+
+    entries.update(new_entries)
+    entries = list(entries)
+    entries.sort()
+
+    with open(Path("dictionaries", "main.txt"), "w") as file:
+        for e in entries:
+            file.write(e+"\n")
+
+    if len(new_entries) > 0:
+        print("\nWrote the below new entries to main.txt:")
+
+    for e in new_entries:
+        print(f"\t {e}")
 
 
 if __name__ == "__main__":
-    po_files = sys.argv[1:]
-    errors = check_spell(po_files)
-    sys.exit(0 if errors == 0 else -1)
+    main()