From efdaf87464a38783991da85bbe398910407560be Mon Sep 17 00:00:00 2001
From: "Torsten Schulz (local)" <tsschulz@gmx.net>
Date: Wed, 26 Aug 2026 14:05:40 +0200
Subject: [PATCH] feat(vocab): refine vocabulary filtering to exclude invalid
 exercise pairs

---
 frontend/src/views/social/VocabLessonView.vue | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/frontend/src/views/social/VocabLessonView.vue b/frontend/src/views/social/VocabLessonView.vue
index ef290dc..355180b 100755
--- a/frontend/src/views/social/VocabLessonView.vue
+++ b/frontend/src/views/social/VocabLessonView.vue
@@ -3663,7 +3663,13 @@ export default {
     _buildMixedPool() {
       if (!this.previousVocab || this.previousVocab.length === 0) return [];
       const currentKeys = new Set(this.trainableLessonVocab.map(v => this.getVocabKey(v)));
-      const filtered = this.previousVocab.filter(v => !currentKeys.has(this.getVocabKey(v)));
+      // Older generated exercises can contain a single word paired with a full
+      // sentence (e.g. "Haus" → "Naa ko sa balay"). Such pairs are neither
+      // valid vocabulary cards nor valid review questions.
+      const filtered = this.previousVocab.filter((v) => (
+        this.isTrainableLessonVocabPair(v?.learning, v?.reference)
+        && !currentKeys.has(this.getVocabKey(v))
+      ));
       const filteredByKey = new Map(filtered.map((v) => [this.getVocabKey(v), v]));
 
       const weakMap = new Map();