Phoneme
A good way to learn phonemes in a language is to learn minimal pairs. A minimal pair is a pair of different words that are different by only one sound. An example of this is "bit" and "bat". Even though only the vowel in each word is different, each word has a completely different meaning. Another example is "dip" and "tip", where both words have different meanings even though only the first consonant in each word is different.