How do you write these words as possessive noun grandmother Sarah boy boss baby bicycle cat uncle father tom?

The possessive forms are:

• grandmother's
• Sarah's
• boy's
• baby's
• bicycle's
• cat's'
• uncle's
• father's
• Tom's

There are two accepted forms for possessive singular nouns ending in s:

• Add an apostrophe (') after the existing s at the end of the Word: boss'
• Add an apostrophe s ('s) after the existing s at the end of the Word: boss's