A minimal pair is a pair of words which differ only in one sound. They are a great way to help your students become more aware of their difficulties with pronunciation. For example, Spanish students often struggle with the pairs "sheet" and "seat", or "cat" and "cut". They can really improve their pronunciation by practising these pairs. The activities below should help them distinguish between the words (listening) and produce the words so the others can understand them (speaking).
Note: these are short activities (5-15 minutes, depending on how much teacher input is necessary). They can focus on just two sounds (e.g. /s/ and /z/) or lots of different sounds - it's up to you. You can find lots of minimal pair examples for problem sounds here (including problems by nationality), or there is a printable pdf here if you want some words to use with the activities.
I would also thoroughly recommend having a look at the book "Pronunciation Games" by Mark Hancock. The pronunciation journey activity in particular is a terrific way to practise minimal pairs.
Idea 1: number dictation
Write the minimal pairs on the board in a table, as in the example opposite. Drill the pronunciation around the class. Then, dictate four of the words, but tell the students they only need to write the number, not the word. For example, if you say "cut, but, ankle, fun" the students should write "1,1,2,1". Then the students work in pairs - one dictates the words, the other says which number.
Idea 2: silent dictation.
Exactly as above, but instead of saying the word, you mouth it silently. Note this only works for sounds which occur in a different place in the mouth - sounds like /p/ and /b/ will look pretty much the same when mouthed!
Idea 3: vocab-grab game
Students work in groups of 3-4. Put a few minimal pair words on slips of paper (one word per paper) and give a set to each group. Then call out a word. The students race to grab the correct word. Keep calling until there's none left - the winner has the most words. Then get the students working within their groups. One student calls out the words, the others grab the word he/she said. Encourage lots of competition to keep them motivated.
Idea 4: object grab
Similar to the activity above, but less preparation. Each pair of students needs an object on the table between them (e.g. an eraser) - they compete against their partner. Then tell the class which sound they are listening for (e.g. /b/). You call out a list of words ("vet, vote, big") and as soon as they hear that sound, they grab the object - if they are right, they get a point.
Idea 5: shouting dictation
A bit noisy, but great to get students exaggerating the mouth shapes. Students work in pairs. Each student has a different set of words which they must dictate to their partner. However, they must stand on opposite sides of the room, so they have to shout. Play background music to make it even more challenging.
Idea 6: stand-up, sit down
As idea 1, you put the table with your minimal pairs on the board. Assign each sound an action. For example, the sound /r/ could be "stand up", and the sound /l/ could be "sit down". Then you call out the words, and the students should perform the action. The last student to do the correct action becomes 'caller' and calls out the next word.
Idea 7: minimal pair bingo
I hated bingo at school - I was too shy to draw attention to myself if I thought I'd won. But lots of students love it. Basically, students choose 9 words from the minimal pairs you give and write them in a 3*3 square. You call out the words and they tick them off as they come up. If they think you've said all the words, they shout "Bingo!"
Idea 8: minimal pair exploration
You need two different minimal pairs for this (e.g. /s/ + /z/, /p/ + /b/). Put some words from each pair on the board and drill them. Assign each of the sounds a direction (e.g. /s/=left, /z/=right, /p/=up, /b/=down). Draw a 5*5 grid on the board. Draw some obstacles and some treasure in the grid. Then give directions by saying the words from the minimal pairs - students follow the directions and say where you end up. Then they draw their own grids and give directions to each other.
Idea 9: minimal pair fruit salad
You could use a few minimal pairs for this - one pair for each 6 - 8 students. Give each student a sound (e.g. for 18 students you could have three students with /s/, three with /z/, three with /r/, three with /l/, three with /b/ and three with /v/). Students sit in a circle. Then you call out a word (e.g. 'right'), and students who have their sound in that word (all the /r/ students) should stand and race to swap seats. It gets increasingly chaotic when there is more than one sound in a word (e.g. 'brings' - /b/, /r/, /z/). You should steal one of the chairs, so one of the students is left standing. That student then calls out another word and tries to steal a seat so another is left standing.