Carry your baby around a room and let them reach for whatever catches their eye.
When a hand lands on something, name it simply and clearly: 'curtain. That is the curtain.' One or two words, not a sentence.
Let them keep touching while you say it again. Follow their reach rather than choosing objects for them.
A word learned at the moment of touching the thing is anchored by touch, sight and sound at once. Following the baby's own reach means you are naming the thing they were already attending to, which is the condition under which labels actually stick.