• isumaqarpunga pikkorissutit, I think you are skilled/proficient
  

  With N{-qaq}V.

• isumaa, his mind [10]
  
• isumamigut, in his (own) mind [10]
  

  This is the vialis 4sg/sg possessive ending, so literally 'through his own mind'. It seems to be common to view thoughts as running through the mind.

In the sense of 'of his own accord', 'by his own intent', etc. If used of a lifeless object: 'of itself', i.e. without any obvious outside cause.

• isumannik aggerpit?, did you come of your own accord? [10]
  

  I.e. not because you were sent by someone.

• isumaminik pigili, let him do it according to his own intent [10]
  
• isumaminnik aggiussissapput, they will/shall bring (something) voluntarily [10]
  

  Kleinschmidt notes [10]: In the sense of 'voluntarily', nammineq isumaminik or isumatsiaaminik is preferred.

• isumaminik aserorpoq, it broke by/of itself [10]
  

  E.g. of something that suddenly shatters. See also nammineq.

See also the combination {isumaqaq}V.

• qanoq isumaqarpa?, what does it mean?
  

  With N{-qaq}V.

• tassa isumaa, that is the meaning of it [10]