How to use the word lack?
Sometimes we use lack of, a lack of, the lack of...I am very confused about these three ..Can anyone explain the differences among them to me by making some sentences, please? Thanks!

Question

Answer

If she fails the exam it will not be for/through lack of effort.
She is a good speaker but she lacks confidence.
We have a lack of storage space in this flat.

Take a look at this link for more examples
https://dictionary.cambridge.org/dictionary/english/lack