Foreshadowing means to show or indicate beforehand.

Thus, in chapter 9 (The Evil Spell),
the title tells me that something unpleasent will happen in this chapter,which is the pouring rain that lasted for the whole chapter. And because of this, leslie thought that an evil spell was casted on Terabithia. the phrase on page 105,"O Spirits of the grove" tells that leslie was trying to talk to the spirits and find ways to overcome this spell. another example would be on page 107,the phrase "horrible realization that it was still raining" tells me that the rain would continue into the next chapter.

In chapter 10 (The Perfect Day),
from the title of this chapter, i can tell that something really pleasent was going to happen as the 'perfect' word was used. 'the perfect day' comes when jess went out with miss edmunds to the national gallery which he had never been there before. "worth anything he had to pay" this phrase,tells me that he had really enjoyed the day with miss edmunds. at the ending of the chapter,the phrase"your girl friend's dead" has already gave me the idea what the next chapter will be about.