Daniel's integrity cannot be questioned. In this sentence given the Abstract noun used is integrity and Concrete noun used is Daniel.
What is a Concrete Noun?
A concrete noun is a noun that can be physically experienced through one of the five senses (taste, touch, sight, hearing, or smell). For example- Would someone please pass me the remote?
What is an Abstract Noun?
An abstract noun is a noun or a noun phrase that represent intangible ideas—things you can't perceive with the five main senses. For example, beauty or freedom, that refers to an idea or a general quality, not to a physical object.
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