This is my brother 2. That's her sister 3. Is this his parent

1,Is this your brother
2,This isn't her brother .
3,Are these their parents

Plural of this that

These these those

Sum up the rules of plural: this that is

1. Generally, s is added, such as birds, persons, dogs, apples, etc;
2. The suffix is ch, SH, s, x plus es, such as dishes, classes, boxes, etc;
3. The ending is a consonant subtitle with y. change y into I and then add es, such as families and babies;
4. The ending is O, plus es, such as: Heroes, tomatos;
5. The suffix is f or Fe. We need to change f or Fe into V and add es, such as leaf - leaves, knife - knives

This is my family photo

These are my family photoes

This is my brother 2. That's her sister 3. Is this his parent