Object clauses (objective clause)

When an object clause introduced by that serves as the object of a verb or certain adjectives, that can be omitted in spoken and informal English, and it often is.

Cases where that cannot be omitted

1. When object clauses introduced by that serve as the object of a verb and the verb is followed by several parallel that-clauses, only the first that, right next to the verb, can be omitted; none of the others can. For example:
   

2. When a that object clause is placed at the start of the sentence for emphasis, that cannot be omitted. For example:

   • That she is a good girl I know. I know that she is a good girl.

   • That he ever said such a thing I simply don’t believe. I simply don't believe he ever said such a thing.

3. When the that-clause is separated from the verb by other words or clauses, that should generally not be omitted, to avoid confusing the meaning. For example:

   • They told us once again that the situation was serious. They told us once more that the situation was serious.

   • The dealer told me how much he was prepared to pay for my car and that I could have the money without delay. The dealer told me what he would pay for my car and said I would receive the money right away.

4. If the verb takes a complex object, i.e. an object + object complement structure, and the object is a that object clause, it is used as a formal object in place of the clause, and the clause is moved to the end of the sentence; in this case that cannot be omitted. For example:
   

5. When a that object clause is the object of certain prepositions, namely except, but and in, that cannot be omitted. Note that apart from these prepositions, that object clauses generally do not serve as objects of prepositions. For example: