A Curiosity of knitting

[FeliksHetalia]

So my sister is a big sewing person, and I'm a big knitter, but I'm also interested in sewing. One thing that I've wanted to do for a long time is knit a fitting garment, but I have a fear of doing so. What I was curious about is whether one can knit the pieces of a sewing project according to their patterns (so what you would normally cut fabric into, you would knit) and then seam them together? I tho