The verbs which require a complement without an object to complete their meanings are called Verbs of Incomplete Predication or Incomplete verbs.
- My father is.
- She looked.
- You seem.
- This building appears.
- Henry will be.
In the above sentences, we observe that the verbs, is, looked, seem, appears and will be, fail to complete their meanings. To complete their meanings, they require a complement.
- My father is happy with my result.
- She looked confident.
- You seem sad today.
- This building appears to be old.
- Henry will be waiting for me.
Now the complements happy with my result; confident; sad today; to be old; and waiting for me complete the meanings of the verbs is, looked, seem, appears and will be, respectively.
Verbs. Therefore, these verbs are called Incomplete verbs.