Si el navegador va lento, uso otro buscador y abro la página en una pestaña nueva.

Because si means if, and that word is written without an accent.

Compare:

• si = if
• sí = yes

So in this sentence, Si el navegador va lento... means If the browser is slow..., not Yes the browser...

Ir is often used in Spanish to talk about how something is working, running, or functioning.

So:

• el navegador va lento = the browser is running slowly / is slow
• es lento = it is slow by nature or it’s a slow one

With technology, Spanish very commonly says things like:

• Mi móvil va fatal.
• El ordenador va muy lento.
• Internet va bien.

So va lento sounds very natural here.

They are two different internet-related words:

• navegador = browser
  Example: Chrome, Firefox, Safari
• buscador = search engine
  Example: Google, Bing, DuckDuckGo

So in the sentence:

• el navegador va lento = the browser is slow
• uso otro buscador = I use another search engine

This is an important distinction because English learners sometimes mix them up too.

Because otro normally does not take un/una before it.

So Spanish says:

• otro buscador = another search engine
• otra página = another page
• otro problema = another problem

Not:

• un otro buscador ❌

This is a very common rule:

• otro / otra / otros / otras usually replaces the indefinite article.

Because this sentence expresses a general habit or a regular action:

• If the browser is slow, I use another search engine and open the page in a new tab.

Spanish often uses the present tense for this kind of general condition:

• Si tengo tiempo, leo.
• Si llueve, me quedo en casa.
• Si el navegador va lento, uso otro buscador.

This is one of the most basic si patterns:

• si + present, present

Yes. Spanish allows both orders.

You can say:

• Si el navegador va lento, uso otro buscador...
• Uso otro buscador... si el navegador va lento.

Both are correct.

When the si clause comes first, it is normally followed by a comma:

• Si el navegador va lento, ...

When it comes second, Spanish often does not use a comma:

• Uso otro buscador si el navegador va lento.

Because lento agrees with navegador, and navegador is a masculine singular noun.

• el navegador → masculine singular
• therefore: lento

If the noun were feminine, you would use lenta:

• la aplicación va lenta
• la página va lenta

So the adjective must match the noun in gender and number.

This is about article choice.

• la página = the page
  It refers to a specific page: the page you are opening.
• una pestaña nueva = a new tab
  It refers to one new tab, not a specific previously known tab.

So Spanish is making the same kind of distinction English does here:

• the page
• a new tab

Also remember:

• página is feminine → la página
• pestaña is feminine → una pestaña nueva

Because abrir algo en... means to open something in...

So:

• abro la página en una pestaña nueva = I open the page in a new tab

This structure is very common:

• Abrí el enlace en otra ventana.
• Ábrelo en una pestaña nueva.
• Voy a abrir el archivo en otra aplicación.

The word en shows the place or context where something is opened.

In Spanish, adjectives usually come after the noun.

So:

• una pestaña nueva
• un navegador lento
• otro buscador
• una página interesante

That is the normal order.

Sometimes adjectives can go before the noun, but that often changes the tone or meaning. In this sentence, una nueva pestaña would usually mean a new tab too, and it is also possible, but una pestaña nueva is a very straightforward, neutral way to say it.

They are easy to confuse because both are common computer words.

• página = page / web page
• pestaña = tab

So:

• abro la página = I open the page
• en una pestaña nueva = in a new tab

A good way to remember it:

• the page is the content
• the tab is the section in the browser where that content appears

Because Spanish often omits subject pronouns when they are clear from the verb form.

• uso already means I use
• abro already means I open

So yo is unnecessary unless you want emphasis or contrast.

Compare:

• uso otro buscador = normal, natural
• yo uso otro buscador = more emphatic, like I use another search engine

This is very normal in Spanish and much more common than in English.