Sin duda, es importante.

It is undoubtedly important.

Breakdown of Sin duda, es importante.

• ser: to be
• importante: important
• sin duda: undoubtedly

Questions & Answers about Sin duda, es importante.

What kind of expression is sin duda?

Sin duda is a fixed adverbial expression. It works like certainly, undoubtedly, or without a doubt in English.

Grammatically, it is made of:

• sin = without
• duda = doubt

Even though it literally looks like without doubt, you should learn it as a set phrase.

Why is there no article before duda?

In Spanish, some fixed expressions use a noun without an article. Sin duda is one of them.

Compare:

• sin duda = a standard expression meaning undoubtedly
• sin la duda would sound unnatural here

This is similar to other common patterns with sin, such as:

• sin problema
• sin miedo
• sin razón

So the short answer is: because this is the normal idiomatic expression.

Why is it es importante and not está importante?