Problem: How does the sentence end?

I tried to fit a kettle into the box but I could not because the
Answer: box was too small.

Problem: How does the sentence end?

Eric is known as bilingual whereas Jason is not because
Answer: Jason still can't speak Spanish fluently.

Problem: How does the sentence end?

The large koi bill purchased would not fit in his new fish tank, the
Answer: tank was too small.

Problem: How does the sentence end?

Because Robert was experiencing hair loss and Brian was not,
Answer:
Robert was jealous of his hair.