I am confused about using the future tense in noun clauses versus time clauses.
I know that the future tense is not used in time clauses, but that it can be used with noun clauses.
However, I am having trouble differentiating between noun clauses and time clauses in a sentence such as:
- I know when he will come.
- I will buy this when he asks me to.
In those two sentences, how can I determine that the dependent clause is acting as a noun clause and not as a time clause?
I am sure that deadrat’s answer is authoritative and complete, but I am going to give you a simpler approach in case you are having trouble with deadrat’s. Maybe mine will be too simple — let’s see.
For each of your sample sentences, let’s see what type of question fits. We should try to write a when question if we can. If that doesn’t work, then we’ll write a when question.
I will use your example sentences, but with a few little changes.
Statement 1: Mama knows when Ricky will come.
Question 1: What does Mama know?
A “when” question wouldn’t work here, so we write a “what” question.
Statement 2: Bruno will buy the new sofa when Papa gives him the money for it.
Question 2: When will Bruno buy the new sofa?
A “when” question works, so we stop there.