Is the word 'ship' the same as the word 'sheep'? Is 'pet' the same as 'bet'? You will notice that these words differ in only one phoneme, yet both are English words. We can say that the two sounds are 'in contrast' and can both be considered phonemes of English. We only have one phoneme on the chart which cannot be tested in this way, and we will return to it at a later point.
Remember that phonemic transcription concerns only the SOUNDS of the language and pays no attention to the orthography.
Pairs of words capable of being distinguished by these contrasts are called minimal pairs.
Try to create your own minimal pairs. A good way to do this is to consider the sound /i:t/ as in 'eat'. How many single consonant phonemes can you put in front of it to create different English words? Then try doing it with other vowel sounds, and other consonants. It is important to realise that phonemes are language specific and what is a meaningful contrast in one language, may not be so in another.
Here are links to a couple of great sites which will help familiarise you with the phonemes.
Below are some minimal pairs which might cause problems for German speakers
You are probably aware of the Japanese confusion between /l, n. r /. This is because there is no such contrast in Japanese.