Question

... Why does not oxygen so + 4 and + 6 Oxidation State like sulphur

Answer 1

bcz oxygen show anamolus behaviour and its size is small then sulphur

Answer 2

Heya!

Here is your answer!
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It is because O2 is the 2nd more electronegative element..oxygen shows positive oxidation state when it is bonded to fluorine  of maximum +2 as in OF2 which means it contains most electronegative element but in other case oxygen shows negative oxidation state in most compounds as it has tendency to accept electron from other less electronegative atom.

So this is why  oxygen dont show oxidation state of more than +2 and less than -2.
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Hope it helps!