Meaning: The birds were singing in the highest branches of the trees.
Choice of Words: "Chirped" is the sound made by some birds. "Treetops" are the highest branches of a tree.
Alternative Expressions
The birds were singing in the trees.
Meaning: This means that you can hear birds making musical sounds from within the trees. It's like saying, I can hear the birds making beautiful sounds from inside the trees.
Choice of Words:The is an article that refers to a specific thing. Birds are animals that can fly. Were is a verb that means to be in a certain place or condition. Singing is a verb that means to make a musical sound with your voice. In is a preposition that means inside or within. The is an article that refers to a specific thing. Trees are tall plants with branches and leaves. When you put them together, "The birds were singing in the trees" means that the birds were making musical sounds from within the trees.
The birdsong filled the air.
Meaning: This means that you can hear birds making sounds all around you. It's like saying, I can hear the birds singing everywhere I go.
Choice of Words:The is an article that refers to a specific thing. Birdsong is a noun that refers to the sounds made by birds. Filled is a verb that means to make something full. The is an article that refers to a specific thing. Air is the invisible gas that we breathe. When you put them together, "The birdsong filled the air" means that the sounds made by the birds were all around us.