You need to distinguish between syllables and words. You have stressed words.
a) I know why he wanted to see you. This sentence could be stressed on any word but 'to', therefore any syllable but 'to' and the 'ed' in 'wanted' - depending on the meaning.
(But we can assume that if a syllable is not stressed in a word, it is not stressed when that word is placed in a sentence).
b) Whatís the time? Yes, or Whatís the time?
Here's how I might stress these two:
c) Donít forget to turn out the light!
d) Itís another beautiful day today.[/quote]