Sú sem getur huggað hana best er systir hennar.

The one who can comfort her best is her sister.

Breakdown of Sú sem getur huggað hana best er systir hennar.

• vera: to be
• geta: to be able
• systirin: the sister
• hana: her

Questions & Answers about Sú sem getur huggað hana best er systir hennar.

What does sú sem mean here?

In this sentence, sú sem means the one who and refers to a female person.

• sú = feminine singular form of sá
• sem = relative particle, like who/that

So sú sem getur huggað hana best is literally something like the female one who can comfort her best.

Why is it sú and not sá?

Because sú is feminine singular.

Icelandic often matches this kind of pronoun to the gender of the person being referred to:

• sá sem = the one who (masculine)
• sú sem = the one who (feminine)
• það sem = that which / what (neuter, often for things or abstract reference)

Here the person is female, and the later phrase systir hennar also confirms that.

What is sem doing, and does it change form?