La incidencia es pequeña.

Because incidencia is a feminine noun in Spanish. In this sentence, the article has to match the noun, so you use la.

A quick pattern:

• la incidencia
• la casa
• la idea

Since incidencia is feminine singular, anything that agrees with it also has to be feminine singular.

Because adjectives in Spanish usually agree with the noun they describe.

Here:

• incidencia = feminine singular
• so the adjective must also be feminine singular
• pequeño → masculine singular
• pequeña → feminine singular

So:

• La incidencia es pequeña
• but El problema es pequeño

We use es because this sentence describes a characteristic or general quality of the subject.

• ser is used for identity, classification, and more permanent or defining descriptions
• estar is used more for temporary states, conditions, or location

Here, small is being presented as a characteristic of la incidencia, so es is the normal choice.

So:

• La incidencia es pequeña = the incidence/impact/issue is small

Using está pequeña would usually sound unnatural here.

It depends on context. Incidencia can mean several related things in Spanish, including:

• incidence in a statistical or technical sense
• impact or effect
• occurrence
• in business, admin, or tech contexts, an issue, problem, or ticket

So even if the meaning has already been given to you, it is useful to know that incidencia is broader in Spanish than English incidence often is.

Normally, no. In a standard sentence like this, Spanish usually needs the article.

So:

• La incidencia es pequeña = natural
• Incidencia es pequeña = not natural in normal Spanish

Spanish often uses the definite article with nouns where English might not use one, especially when talking about a known concept, category, or measure.

It is grammatically correct, but depending on the context, Spanish speakers might often prefer a different adjective.

For example, if you are talking about a rate, frequency, or statistical incidence, these may sound more natural:

• La incidencia es baja
• La incidencia es reducida

Pequeña is still understandable and correct, but baja is often more idiomatic for things like rates, levels, or incidence.

In standard Peninsular Spanish, approximately:

la in-thi-DHEN-thya es pe-KE-nya

A few key pronunciation points:

• c before i is usually pronounced like th in think in most of Spain
• ñ sounds like ny in canyon
• the stress falls on:
  • incidencia → den
  • pequeña → ke

A more phonetic version:

• incidencia → in-thi-DHEN-thya
• pequeña → pe-KE-nya

It follows a very common Spanish pattern:

• La incidencia = subject
• es = verb
• pequeña = adjective / description

So the structure is:

subject + ser + adjective

This is very similar to English:

• The incidence is small
• The problem is minor
• The house is big

Usually not. With incidencia, pequeña is normally understood in a more abstract sense, such as:

• low in amount
• minor in importance
• limited in effect
• small in scale

So the sentence is generally about degree or significance, not physical size.