I think the word väldigt is very similar to the German gewaltig you just use the väldigt -waltig and we don't put a t behind.
But the difference is that gewaltig isn't the same meaning as väldigt.
Utmattade in german would be maybe ausgemachte?
Sömnig is exactly the same in Portuguese 'Sono' pronounced sónoo. Cones this word from Latin?
Also mat and utmattade are similar to matar in Portuguese.