diff --git a/Lib/glyphsets/test_strings.json b/Lib/glyphsets/test_strings.json
index ba21a77118..6f9c107b2e 100644
--- a/Lib/glyphsets/test_strings.json
+++ b/Lib/glyphsets/test_strings.json
@@ -1,35 +1,110 @@
 {
     "GF_Latin_Kernel": {
         "Letter Groups": [
-            "EFHIJLTU", 
-            "AVWXZ",
-            "KMNY",
-            "COQS",
-            "BPRDG",
-            "fijltr",
-            "kvwxyz",
-            "hmnu",
-            "ceogs",
-            "abdpq"
+            {
+                "string": "EFHIJLTU",
+                "lang": "en"
+            },
+            {
+                "string": "AVWXZ",
+                "lang": "en"
+            },
+            {
+                "string": "KMNY",
+                "lang": "en"
+            },
+            {
+                "string": "COQS",
+                "lang": "en"
+            },
+            {
+                "string": "BPRDG",
+                "lang": "en"
+            },
+            {
+                "string": "fijltr",
+                "lang": "en"
+            },
+            {
+                "string": "kvwxyz",
+                "lang": "en"
+            },
+            {
+                "string": "hmnu",
+                "lang": "en"
+            },
+            {
+                "string": "ceogs",
+                "lang": "en"
+            },
+            {
+                "string": "abdpq",
+                "lang": "en"
+            }
         ],
         "Spacing": [
-            "HHOHHOOHOO HIHOIO",
-            "uuonouonoo ninoioolonlniuo",
-            "010 080 030 020 050 060 070"
+            {
+                "string": "HHOHHOOHOO HIHOIO",
+                "lang": "en"
+            },
+            {
+                "string": "uuonouonoo ninoioolonlniuo",
+                "lang": "en"
+            },
+            {
+                "string": "010 080 030 020 050 060 070",
+                "lang": "en"
+            }
         ],
         "Kerning": [
-            "HHAVAHH WAFAPATAUAYALYTJĿLVÆ HH",
-            "TiTíTîTïTìTĭTīTĩT Vă Tä Tü Tõ Tŭ Tř",
-            "HHTan oTo yTy vAv oVo eYe Ly Ky Ac",
-            "nin non nvn ovo oxo ayn fl fi fj ft gj ko rento",
-            "ďá ďu ŀl gj ľk włw yły ółr fħ ílïlîl",
-            "H.Y-Y.T,F.P,V:Y„V-T-A*A’A“A’A-AL–L—L-",
-            "n.r.r,y.y,(o)(i)(d)(j)(f)[j]{f}",
-            "080 076 474 973 94 7078",
-            "P4T47A .47,9.7-»4",
-            "42°21′29″N 71°03′49″W",
-            "d² m³ 15°C/26°F",
-            "0/0\\0"
+            {
+                "string": "HHAVAHH WAFAPATAUAYALYTJĿLVÆ HH",
+                "lang": "en"
+            },
+            {
+                "string": "TiTíTîTïTìTĭTīTĩT Vă Tä Tü Tõ Tŭ Tř",
+                "lang": "en"
+            },
+            {
+                "string": "HHTan oTo yTy vAv oVo eYe Ly Ky Ac",
+                "lang": "en"
+            },
+            {
+                "string": "nin non nvn ovo oxo ayn fl fi fj ft gj ko rento",
+                "lang": "en"
+            },
+            {
+                "string": "ďá ďu ŀl gj ľk włw yły ółr fħ ílïlîl",
+                "lang": "en"
+            },
+            {
+                "string": "H.Y-Y.T,F.P,V:Y„V-T-A*A’A“A’A-AL–L—L-",
+                "lang": "en"
+            },
+            {
+                "string": "n.r.r,y.y,(o)(i)(d)(j)(f)[j]{f}",
+                "lang": "en"
+            },
+            {
+                "string": "080 076 474 973 94 7078",
+                "lang": "en"
+            },
+            {
+                "string": "P4T47A .47,9.7-»4",
+                "lang": "en"
+            },
+            {
+                "string": "42°21′29″N 71°03′49″W",
+                "lang": "en"
+            },
+            {
+                "string": "d² m³ 15°C/26°F",
+                "lang": "en"
+            },
+            {
+                "string": "0/0\\0",
+                "lang": "en"
+            }
         ]
     }
 }
\ No newline at end of file