Mark the stressed syllable in each sentence: i These excellent novels belong to my grandmother. ii Do you have a pen to lend? iii Open your book to page number 165. iv The rain in Spain falls mainly on the plains. v When I reached the station, the train had left.

To mark the stressed syllable in each sentence, we can indicate the stressed syllables with an apostrophe (') before the stressed vowel. Here are the stressed syllables marked in each sentence:

i. These excellent novels belong to my grandmother.

• Stressed syllable: exCELlent

ii. Do you have a pen to lend?

• Stressed syllable: PEN

iii. Open your book to page number 165.

• Stressed syllables: O-pen, BOOK, NUM-ber

iv. The rain in Spain falls mainly on the plains.

• Stressed syllables: RAIN, SPAIN, MAIN-ly, PLAINS

v. When I reached the station, the train had left.

• Stressed syllables: REAched, STA-tion, TRAIN, LEFT

In English, stress often falls on specific syllables within words to emphasize them in speech. These stressed syllables are typically pronounced with slightly higher pitch, longer duration, and louder volume compared to unstressed syllables.