The glottal stop /ʔ/ and how to make it
The glottal stop is not used as a stand alone phoneme in EL learner dictionaries, so it is not included on the Sound Foundations pronunciation chart. Nor is the glottal stop indicated in English spelling. However in some languages the glottal stop is shown as a natural part of the spelling system (see this Wikipedia article for a brief discussion). Nevertheless the glottal is frequently encountered in English language teaching and materials.
In the IPA (International Phonetic Alphabet) the glottal stop is transcribed /ʔ/ like a question mark without the dot. The glottal stop is unvoiced and is produced by closing the glottis at the back of the mouth which stops the airflow. Hence this is a stop sound. This stop to the airflow also stops any voicing so the glottal stop is also voiceless. This characteristic way of stopping the airflow gives the glottal stop its characteristic and identifiable resonance. It’s full description would be a voiceless glottal stop.
The glottal stop is used in many varieties of English as an allophone of /t/. This is especially typical in Cockney eg butter as bu’er or /bʌʔǝ/ and where the /t/ is followed by a syllabic /m/ as in bottom or syllabic /n/ as in button or syllabic /l/ as in bottle or indeed glottal
Last month I was external pronunciation tutor on the excellent Oxford TEFL Diploma and I quote here from one of our exchanges about the glottal stop.
Course member Liam MacCarron wrote
1) How do you propose we help our learners with the glottal stop.
2) If you had been introducing the phonemes of words on the board to students for a few weeks, how would you represent the glottal stop even though it isn’t represented on the phonemic chart? Should we just use that question mark looking symbol, tell them that’s what it represents and move on? Or would that a nice intro to allophones for them?
Hi Liam, I would help them in the same way as for any other sound. They can easily find the glottal stop sound by by saying any vowel repeatedly and quickly, for example /iː…iː….iː….iː…/ or /ʊ…ʊ…ʊ…ʊ…./ or /ʌ…ʌ…ʌ…ʌ…/ and then slowing down the repetition to the point where you can isolate the way the air flow is stopped between each vowel repetition. For most learners it is not a new or unfamiliar sound even if it is not a regular part of their first language.
Placing the glottal stop on the chart
As soon as they have isolated and can say the glottal stop I would give it the symbol /ʔ/ like a question mark without a dot, I would draw it on the board next to the chart, in a little box the same size as the boxes on the chart symbols and boxes on the chart. and I would place this new symbol at the end of the plosive row (the first row) of consonants, to the right of /g/ . This is in fact the correct place for it to go as it is a stop, is unvoiced and produced is at the back of the vocal apparatus.
Once you have got it on the chart like this the sound is available for recognition and production along with all the other sounds for making words, tracking connected speech and so on.
If you are using the glottal stop as an allophone of /t/ you can also indicate that it can be regarded as belonging in space in the /t/ box
When practising I would get learners to say the word (eg butter) one way with the glottal stop /ʔ/ and the other way with /t/, so they don’t get fixated on one or the other and can feel the difference in their mouths and be able to hear the distinction more discerningly.