It might be a variegated Ti plant, but I'm not sure. It looks like the leaf tips are turning brown. With most plants, that means the roots are damaged. Root damage could be from disease or insects, but most of the time it is from watering. It looks like you have the plant in a terra cotta colored plastic pot inside a white cache pot. If the white pot does not have a drainage hole, the plant's roots are probably staying too wet and rotting. I would take it out of the outer pot and not water it until the soil is dry to the touch in the first half-inch of potting soil (poke your finger in to check). Then, just give it a little water. Try to keep it just barely moist but never wet or completely dry until it has recovered. You will know it has recovered when it grows some healthy new leaves. I hope this helps.

it's a variegated ginger. If it's not draining, the plant could be sensitive to the salt accumulation from the tap water too.

As far as I see, the plant is draining. Both the inner pot, made of plastic, and the outer, have ample drainage holes. I do think, however, they problem started when I kept the soil too wet. I am pretty sure our tap water comes from a glacial lake source. Can there be salt in our water, if that is the case? If the problem is tap water salt, how do I correct that? The plant is sitting on a shady window ledge now, drying out from its last watering.

Possibly suffering from wind burn if in an exposed area