I planted a pineapple plant. Some leaves died. Tips of others died too. But, as you can see in the picture, most of it is green. It has been this way for months, and no new leaves grow. Is it dead? If not, what should I do to encourage growth?
It's not dead at all - but there are some dead areas at the tips of the leaves, and what looks like one completely dead leaf. Trim off the dead areas and the dead leaf,but don't prune. These plants grow from the centre, and if you're in the northern hemisphere, it will now rest and not do very much. Even indoors, though, it needs as much as sun as it can get, but should not be anywhere near a heat source like a radiator or fire. As far as watering goes, only water when the surface of the potting soil feels dry to the touch, and water well, emptying away any excess water in an outer tray or pot after 30 minutes, never leave it sitting in water. Further information here, https://www.todayshomeowner.com/how-to-grow-pineapples-as-houseplants/ - the bit you're interested in is towards the end. You'll note the size of pot required, and the fact that these plants benefit from being outdoors during summer.
I'm rather curious as to the cause of the white lines or what look like scratch marks on some of the central leaves...