The interesting thing about hirigana is that they ALWAYS make the same sound, unlike English. For a different sound marks are put up and to the right of the hiragana (see the chart below) or a 'marker' is put smaller and to the right of the hiragana (see chart below).
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| http://www.tanos.co.uk/jlpt/jlpt5/kana/kana2.jpg |
