|Men's sweaters often have neck bands that are too tight. The strain of pulling it on over the head will eventually break the stitching. Sometimes, a man wears finger-shaped holes in the front by pulling in the same place.
A man's crew-neck sweater needs a neck band that can be easily stretched to 24".
To repair a too-small neck opening: First, choose some spare yarn in a color that will blend with the sweater. Remove the neckband and ravel it so you can use the yarn. Now use a yarn needle, threaded with your spare yarn, to make running stitches to mark the seam line for the new band.
Using a crochet hook, with the right side of the sweater facing you, pick up and knit stitches all around the neck. Work a 2-knit, 2-purl rib on a circular needle for several rows, alternating your spare yarn with the yarn you ravelled from the neck band. A 2X 2 rib will both shrink up more and stretch out more than a 1X1 rib. Rib to 1" deep. Put your few rows on a string and try on the sweater.
If the ribbed-on rows are too tight, rip out and pick up and knit more stitches. If the rows are too loose, reduce by a percentage: for 25% reduction, for example, take every 4th set of 2 purls and purl them into one purl. The purl stitches recede, so the reductions will not be noticable. Other than the reductions, maintain the rib pattern.
When the rows are 2" deep, put the stitches on a string again and try the neck once more. If too shallow, rib some more. When the depth is sufficient, bind off in ribbing, maintaining the rib pattern. Weave in ends.
Block the neckline to encourage the new ribbing to shrink closed at the bound-off edge.
Now tell your man to put on the sweater like this: first insert arms, then use BOTH HANDS to gather the neck opening. Slide neck opening over head and slide the hands out. Any adjustments should be made with the fingers of both hands curled inside the neck band.