diff --git a/src/main/java/org/ids_mannheim/PaddedSlidingWindowQueue.java b/src/main/java/org/ids_mannheim/PaddedSlidingWindowQueue.java
new file mode 100644
index 0000000..7c141bd
--- /dev/null
+++ b/src/main/java/org/ids_mannheim/PaddedSlidingWindowQueue.java
@@ -0,0 +1,47 @@
+package org.ids_mannheim;
+
+
+import static org.ids_mannheim.TotalNGrams.logger;
+
+public class PaddedSlidingWindowQueue extends SlidingWindowQueue {
+    public static final String TEXT_END_SYMBOL = "«END»";
+    public static final String TEXT_START_SYMBOL = "«START»";
+    public static final String TEXT_STARTEND_POS = "«STARTEND»";
+    private static String TEXT_START_COMBO, TEXT_END_COMBO;
+    private boolean needsFlush;
+
+    public PaddedSlidingWindowQueue(int size, Increaser flush, boolean with_lemma_and_pos) {
+        super(size, flush, with_lemma_and_pos);
+        if (with_lemma_and_pos) {
+            TEXT_START_COMBO = TEXT_START_SYMBOL + '\t' + TEXT_START_SYMBOL + '\t' + TEXT_STARTEND_POS;
+            TEXT_END_COMBO = TEXT_END_SYMBOL + '\t' + TEXT_END_SYMBOL + '\t' + TEXT_STARTEND_POS;
+        } else {
+            TEXT_START_COMBO = TEXT_START_SYMBOL;
+            TEXT_END_COMBO = TEXT_END_SYMBOL;
+        }
+        logger.info("Using padding.");
+        needsFlush = false;
+    }
+
+    @Override
+    public void reset(int fold) {
+        this.clear();
+        for (int i = 0; i < maxSize; i++)
+            add(TEXT_START_COMBO);
+        this.fold = fold;
+    }
+
+    @Override
+    public void add(String k) {
+        super.add(k);
+        needsFlush = true;
+    }
+
+    @Override
+    public void textBreak() {
+        if (needsFlush)
+            for (int i = 0; i < maxSize; i++)
+                add(TEXT_END_COMBO);
+    }
+
+}
diff --git a/src/main/java/org/ids_mannheim/SlidingWindowQueue.java b/src/main/java/org/ids_mannheim/SlidingWindowQueue.java
index 93acd58..32e0f60 100644
--- a/src/main/java/org/ids_mannheim/SlidingWindowQueue.java
+++ b/src/main/java/org/ids_mannheim/SlidingWindowQueue.java
@@ -3,17 +3,15 @@
 import java.util.LinkedList;
 
 public class SlidingWindowQueue extends LinkedList {
-    private final int maxSize;
-    private final Increaser flush;
+    final int maxSize;
+    final Increaser flush;
+    final boolean with_lemma_and_pos;
     public int fold;
 
-    interface Increaser {
-        void accept(String s);
-    }
-
-    public SlidingWindowQueue(int size, Increaser flush) {
+    public SlidingWindowQueue(int size, Increaser flush, boolean with_lemma_and_pos) {
         this.maxSize = size;
         this.flush = flush;
+        this.with_lemma_and_pos = with_lemma_and_pos;
     }
 
     public void add(String k) {
@@ -28,4 +26,11 @@
         this.clear();
         this.fold = fold;
     }
+
+    public void textBreak() {
+    }
+
+    interface Increaser {
+        void accept(String s);
+    }
 }
diff --git a/src/main/java/org/ids_mannheim/TotalNGrams.java b/src/main/java/org/ids_mannheim/TotalNGrams.java
index 86932d4..ee1b665 100644
--- a/src/main/java/org/ids_mannheim/TotalNGrams.java
+++ b/src/main/java/org/ids_mannheim/TotalNGrams.java
@@ -92,6 +92,11 @@
             "--numeric-secondary-sort"}, description = "Sort entries with same frequency numerically  (default: ${DEFAULT-VALUE})")
     boolean numericSecondarySort = false;
 
+    @SuppressWarnings("CanBeFinal")
+    @CommandLine.Option(names = {
+            "--pad"}, description = "Add padding " + PaddedSlidingWindowQueue.TEXT_START_SYMBOL + " and " + PaddedSlidingWindowQueue.TEXT_END_SYMBOL + " symbols at text edges  (default: ${DEFAULT-VALUE})")
+    boolean addPadding = false;
+
     private Progressbar etaPrinter;
 
     public TotalNGrams() {
@@ -164,7 +169,7 @@
         int threads = Math.min(max_threads, inputFiles.size());
         logger.info("Processing fold " + fold + "/" + FOLDS);
         logger.info("Using " + threads + " threads");
-        IntStream.range(0, threads).forEach(unused -> es.execute(new Worker(queue, inputFiles, ngram_size, fold, FOLDS, map, with_lemma_and_pos, downcase_tokens, workerNodePool, etaPrinter, logger)));
+        IntStream.range(0, threads).forEach(unused -> es.execute(new Worker(queue, inputFiles, ngram_size, fold, FOLDS, map, with_lemma_and_pos, downcase_tokens, workerNodePool, etaPrinter, logger, addPadding)));
         queue.addAll(IntStream.range(0, inputFiles.size()).boxed().collect(Collectors.toList()));
         IntStream.range(0, threads).forEach(unused -> {
             try {
diff --git a/src/main/java/org/ids_mannheim/Worker.java b/src/main/java/org/ids_mannheim/Worker.java
index ca7f27c..2f6b32b 100644
--- a/src/main/java/org/ids_mannheim/Worker.java
+++ b/src/main/java/org/ids_mannheim/Worker.java
@@ -29,13 +29,14 @@
     private final WorkerNodePool pool;
     private final boolean with_lemma_and_pos;
     private final boolean downcase_tokens;
+    private final boolean addPadding;
 
     private final DeterministicRandomProvider deterministicRandomProvider;
 
     public Worker(BlockingQueue<Integer> queue, ArrayList<String> fnames, int ngram_size, int target_fold, int folds,
                   ConcurrentHashMap<String, AtomicInteger> map,
                   boolean with_lemma_and_pos, boolean downcase_tokens, WorkerNodePool pool,
-                  Progressbar etaPrinter, Logger logger) {
+                  Progressbar etaPrinter, Logger logger, boolean addPadding) {
         this.queue = queue;
         this.fnames = fnames;
         this.map = map;
@@ -47,6 +48,7 @@
         this.logger = logger;
         this.deterministicRandomProvider = new DeterministicRandomProvider(folds);
         this.downcase_tokens = downcase_tokens;
+        this.addPadding = addPadding;
     }
 
     @Override
@@ -55,7 +57,8 @@
             int index = queue.take();
             int retries = MAX_RETRIES;
             int texts = 0;
-            SlidingWindowQueue slidingWindowQueue = new SlidingWindowQueue(ngram_size, s -> FoldedEntry.incr(map, s));
+            SlidingWindowQueue slidingWindowQueue = (addPadding ? new PaddedSlidingWindowQueue(ngram_size, s -> FoldedEntry.incr(map, s), with_lemma_and_pos) :
+                    new SlidingWindowQueue(ngram_size, s -> FoldedEntry.incr(map, s), with_lemma_and_pos));
             while (index >= 0) {
                 String fname = fnames.get(index);
                 File current_file = new File(fname);
@@ -113,6 +116,7 @@
                     if (line.startsWith("#")) {
                         Matcher matcher = new_text_pattern.matcher(line);
                         if (matcher.find()) {
+                            slidingWindowQueue.textBreak();
                             fold = deterministicRandomProvider.getFoldFromTextID(matcher.group(1)) + 1;
                             texts++;
                             if (fold == target_fold) {
@@ -124,7 +128,7 @@
                         if (strings.length < 4) {
                             continue;
                         }
-                        assert strings.length == 10 : "CoNLL-U Format must have 10 columns";
+                        assert strings.length == 10 : "Error: CoNLL-U Format must have 10 columns in line \""+line+"\"";
                         String token = ( downcase_tokens?
                                 Utils.unEscapeEntities(strings[1]).toLowerCase(Locale.ROOT) :
                                 Utils.unEscapeEntities(strings[1]));
@@ -156,6 +160,7 @@
                         }
                     }
                 }
+                slidingWindowQueue.textBreak();
                 pool.markFree(poolIndex);
                 if (texts > 0) {
                     logger.info(pool.getHost(poolIndex) + " finished " + fname + " with " + texts + " texts");