Lucas's or Lucas'?

Lucas’s is the standard singular possessive form for the name Lucas endorsed by the Chicago Manual of style e.g “Lucas’s cooking always brings joy to family dinners.”

Furthermore Lucas’ is another singular possessive for Jonas stipulated by the AP stylebook e.g. Family trips are more fun with Lucas’s playlist.

The different forms of the term Lucas are summarized in the following chart below

Form	Example
Singular	Lucas
Singular possessive	Lucas’/ Lucas’s
Plural	Lucases
Plural possessive	Lucases

Lets now see how the above forms can be used in context:

Singular possessive: Lucas’ resilience in overcoming challenges is truly inspiring.

Singular possessive: The team relies on Lucas’ expertise in data analysis.

Plural: The Lucases love spending weekends together.

Plural possessive: The Lucases’ annual camping trips bring the family closer.

From the above, you can see that there are two forms for the singular possessive for the name Lucas; Lucas’s and Lucas’.

The standard plural is Lucases. Use Lucases when you are referring to a group of family members with the surname name Lucas or multiple individuals named Lucases.

Lucases from different generations share stories during family gatherings.
The Lucases decided to start a book club.
Lucases around the world celebrate New Year’s in various ways.

Lucas’s

The term Lucas’s with an apostrophe and ‘s’ at the standard singular possessive form for the name Lucas. It’s the more common form of the two and is endorsed by the Chicago mManual of Style.

Use Lucas’s when you are trying to refer to something that belongs to a person named Lucas.

Lucas’s determination in pursuing his goals is truly inspiring.
At the family reunion, everyone enjoyed Lucas’s storytelling.
The team celebrated Lucas’s achievement with a surprise party.
During the trip, we relied on Lucas’s navigation skills.
Lucas’s leadership qualities shine through in group projects.

In some literatures, the ‘s’ is often omitted from this term when the following word is starting with an ‘s’. Both the Chicago Manual of Style and the AP Stylebook do allow it

Lucas’

Lucas’ is also another alternative possessive form for the term for the name Lucas. Lucas’ is less commonly used in modern English. However it’s just as grammatically correct as the term Lucas’s and is endorsed by the associated press stylebook.

If you choose to use any of these two singular possessive forms, stick to one that you have picked throughout the document you are editing.

The success of the event was largely due to Lucas’ organizational skills.
Lucas’ role as the team captain is crucial for our success.
Lucas’ compassion for animals is evident in his volunteer work at the shelter.
The project’s timeline was met thanks to Lucas’ efficient time management.
During the trip, we enjoyed Lucas’ culinary skills in preparing delicious meals.
Lucas‘ role as a mentor has positively impacted many aspiring professionals.
At family gatherings, Lucas’ sense of humor keeps everyone entertained.

Some people do prefer to use this form because it’s much easier to pronounce when the next word starts with an s.

However it’s still correct to write Lucas’s when the next word starts with an “s”

Lucases’

Lucases’ with an apostrophe added to the plural form Lucases, is the standard plural possessive of the them Lucas. Use it when you are referring to something that belongs to multiple individuals named Lucases’ or to family members named Lucas.

It follows the English rule that dictates that you add an apostrophe to plurals of proper nouns that end in s.