Here are some examples of how to use "lumber" as a verb in a sentence:
* The old man lumbered across the room, his joints aching.
* The bear lumbered through the forest, searching for food.
* The ship lumbered through the waves, its sails straining in the wind.
If you want to use "lumber" as a noun in a sentence, you could say:
* The carpenter used lumber to build a table.
* The lumberyard is full of different types of wood.
* The price of lumber has increased recently.
Remember to choose the correct form of the word depending on the meaning you want to convey.