diff --git a/app/src/main/java/eu/faircode/email/EditTextCompose.java b/app/src/main/java/eu/faircode/email/EditTextCompose.java
index 43acda551b..69c618e6b7 100644
--- a/app/src/main/java/eu/faircode/email/EditTextCompose.java
+++ b/app/src/main/java/eu/faircode/email/EditTextCompose.java
@@ -49,6 +49,7 @@ import android.view.inputmethod.InputConnectionWrapper;
 import android.widget.EditText;
 import android.widget.Toast;
 
+import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.view.inputmethod.EditorInfoCompat;
 import androidx.core.view.inputmethod.InputConnectionCompat;
 import androidx.core.view.inputmethod.InputContentInfoCompat;
@@ -112,8 +113,14 @@ public class EditTextCompose extends FixedEditText {
                 public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                     try {
                         int order = 1000;
-                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_insert_brackets, order++, context.getString(R.string.title_insert_brackets));
-                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_insert_quotes, order++, context.getString(R.string.title_insert_quotes));
+                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_insert_brackets,
+                                order++, context.getString(R.string.title_insert_brackets));
+                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_insert_quotes,
+                                order++, context.getString(R.string.title_insert_quotes));
+                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_dictionary_add,
+                                order++, context.getString(R.string.title_dictionary_add));
+                        menu.add(Menu.CATEGORY_SECONDARY, R.string.title_dictionary_delete,
+                                order++, context.getString(R.string.title_dictionary_delete));
                     } catch (Throwable ex) {
                         Log.e(ex);
                     }
@@ -125,8 +132,18 @@ public class EditTextCompose extends FixedEditText {
                     int start = getSelectionStart();
                     int end = getSelectionEnd();
                     boolean selection = (start >= 0 && start < end);
+                    Context context = getContext();
+                    Editable edit = getText();
+                    boolean dictionary = (BuildConfig.DEBUG &&
+                            context instanceof AppCompatActivity &&
+                            LanguageTool.isPremium(context) &&
+                            selection &&
+                            edit != null &&
+                            edit.subSequence(start, end).toString().indexOf(' ') < 0);
                     menu.findItem(R.string.title_insert_brackets).setVisible(selection);
                     menu.findItem(R.string.title_insert_quotes).setVisible(selection);
+                    menu.findItem(R.string.title_dictionary_add).setVisible(dictionary);
+                    menu.findItem(R.string.title_dictionary_delete).setVisible(dictionary);
                     return false;
                 }
 
@@ -138,6 +155,10 @@ public class EditTextCompose extends FixedEditText {
                             return surround("(", ")");
                         else if (id == R.string.title_insert_quotes)
                             return surround("\"", "\"");
+                        else if (id == R.string.title_dictionary_add)
+                            return modifyDictionary(true);
+                        else if (id == R.string.title_dictionary_delete)
+                            return modifyDictionary(false);
                     }
                     return false;
                 }
@@ -167,6 +188,50 @@ public class EditTextCompose extends FixedEditText {
                     }
                     return selection;
                 }
+
+                private boolean modifyDictionary(boolean add) {
+                    int start = getSelectionStart();
+                    int end = getSelectionEnd();
+                    if (start < 0 || start >= end)
+                        return false;
+
+                    final Context context = getContext();
+                    if (!(context instanceof AppCompatActivity))
+                        return false;
+                    AppCompatActivity activity = (AppCompatActivity) getContext();
+
+                    Editable edit = getText();
+                    if (edit == null)
+                        return false;
+
+                    String word = edit.subSequence(start, end).toString();
+
+                    Bundle args = new Bundle();
+                    args.putString("word", word);
+                    args.putBoolean("add", add);
+
+                    new SimpleTask<Void>() {
+                        @Override
+                        protected Void onExecute(Context context, Bundle args) throws Throwable {
+                            String word = args.getString("word");
+                            boolean add = args.getBoolean("add");
+                            LanguageTool.modifyDictionary(context, word, null, add);
+                            return null;
+                        }
+
+                        @Override
+                        protected void onExecuted(Bundle args, Void data) {
+                            setSelection(end);
+                        }
+
+                        @Override
+                        protected void onException(Bundle args, Throwable ex) {
+                            ToastEx.makeText(getContext(), ex.toString(), Toast.LENGTH_LONG).show();
+                        }
+                    }.execute(activity, args, "dictionary:modify");
+
+                    return true;
+                }
             });
 
             setCustomInsertionActionModeCallback(new ActionMode.Callback() {
diff --git a/app/src/main/java/eu/faircode/email/LanguageTool.java b/app/src/main/java/eu/faircode/email/LanguageTool.java
index 8b7d98f03b..62dd7bdb86 100644
--- a/app/src/main/java/eu/faircode/email/LanguageTool.java
+++ b/app/src/main/java/eu/faircode/email/LanguageTool.java
@@ -295,6 +295,13 @@ public class LanguageTool {
             }
     }
 
+    static boolean isPremium(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        String lt_user = prefs.getString("lt_user", null);
+        String lt_key = prefs.getString("lt_key", null);
+        return (!TextUtils.isEmpty(lt_user) && !TextUtils.isEmpty(lt_key));
+    }
+
     private static void checkStatus(HttpsURLConnection connection) throws IOException {
         int status = connection.getResponseCode();
         if (status != HttpsURLConnection.HTTP_OK) {
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 4d30d7525c..82043e30b4 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1966,6 +1966,8 @@
     <string name="title_select_block">Select block</string>
     <string name="title_insert_brackets">Bracket</string>
     <string name="title_insert_quotes">Quote</string>
+    <string name="title_dictionary_add" translatable="false">Add word</string>
+    <string name="title_dictionary_delete" translatable="false">Delete word</string>
     <string name="title_add">Add</string>
     <string name="title_browse">Open with</string>
     <string name="title_info">Info</string>