During a speaking activity the other day, I heard one of my B1 adults say /ʃaɪld/. This isn’t uncommon in our corner of Andalucía, where the /tʃ/ phoneme is often pronounced /ʃ/ and in fact during my Diploma, I chose that specific problem for my phonology presentation. Seeing a teachable moment, I quickly jotted down some minimal pairs with those sounds on the board.
We drilled the words individually and some students commented on how difficult they found it to differentiate between the two sounds.
I then asked them to write a sentence in pairs using as many of the words as possible and you can see their ideas in the picture below.
We then practised the sentences as a class and in pairs – and even I found it difficult to say them at speed!

I’ve recently been doing some work with phonology with my 10-year-olds, trying to familiarise them with the phonetic alphabet.  A quick and easy way to raise awareness of English sounds is with a discrimination activity:

• Divide the class into pairs and give each a mini-whiteboard.
• Dictate a number of words to them.  The words should contain one of the two phonemes you want to focus on.
• In whole group feedback, write the words on the board.
• Then write up the two phonemes and tell learners to work in pairs to categorise each word according to the phoneme it contains.
• After checking, you can either do some kinaesthetic controlled practice – such as jumping to one side or the other depending on the phoneme they hear – or a freer activity, such as using four of the words in a dialogue.

This activity is especially useful to highlight the spelling-sound difference, for example, /dʒ / in jeans and genius or /i:/ in beach, green or people.