他的惯用手不明确，书写偏用左手，握笔姿势正常，右手亦可书写，但较左手落

他的惯用手不明确，书写偏用左手，握笔姿势正常，右手亦可书写，但较左手落笔用力。

結果 (英文) 1:

His dominant hand is not clear, he uses his left hand to write, and holds a pen in a normal posture. He can also write with his right hand, but he writes harder than his left.

結果 (英文) 2:

His habitual hand is not clear, writing with his left hand, holding pen posture is normal, right hand can also write, but it is harder than left hand.

結果 (英文) 3:

His usual hands are not clear, writing with the left hand, holding the pen posture is normal, the right hand can also write, but more than the left hand pen force.