Ferme cet onglet et clique sur l’icône bleue en haut de l’écran.

Because this sentence uses the informal imperative: it is giving instructions to one person using tu.

With -er verbs in the tu imperative, French normally drops the final -s:

• tu fermes → Ferme !
• tu cliques → Clique !

So:

• Ferme cet onglet
• Clique sur l’icône bleue

A useful thing to remember: this dropping of -s is especially common with regular -er verbs in the imperative.

Onglet is a masculine singular noun, so the basic demonstrative adjective would be ce.

But French uses cet instead of ce when a masculine singular noun begins with a vowel sound (or a silent h), to make pronunciation smoother.

So:

• ce livre
• ce bouton
• cet onglet
• cet écran

It is not cette, because cette is for feminine singular nouns.

Because icône begins with a vowel sound, and French normally avoids putting la directly before a vowel.

So la becomes l’ by elision:

• la table
• la fenêtre
• l’icône
• l’image

You can still tell that icône is feminine from the adjective bleue, which also shows feminine agreement.

Because icône is a feminine noun, and adjectives usually agree with the noun they describe.

So:

• masculine singular: bleu
• feminine singular: bleue
• masculine plural: bleus
• feminine plural: bleues

Here:

• l’icône = feminine singular
• therefore: l’icône bleue

This is a very common pattern in French: adjectives often change form to match gender and number.

In French, most adjectives come after the noun, not before it.

So English:

• the blue icon

becomes French:

• l’icône bleue

Many very common adjectives can come before the noun, but color adjectives like bleu / bleue usually come after.

So this word order is completely normal.

Here, sur is part of the standard expression cliquer sur, which means to click on.

So:

• cliquer sur un lien = to click on a link
• cliquer sur une icône = to click on an icon

Even though sur often literally means on, in this case it is just the normal preposition used with cliquer.

So clique sur l’icône bleue is the natural way to say click on the blue icon.

En haut de means at the top of.

So:

• en haut de l’écran = at the top of the screen

Breakdown:

• en haut = at the top / up top
• de = of
• l’écran = the screen

You will often see similar expressions:

• en bas de la page = at the bottom of the page
• en haut de la fenêtre = at the top of the window
• à gauche de l’image = to the left of the image

Because écran begins with a vowel, and le becomes l’ before a vowel.

The full form is:

• de + l’écran

not

• de écran

And not

• du écran

because du only comes from de + le, and before a vowel French uses l’, not le.

Compare:

• en haut du bureau = at the top of the desk
• en haut de l’écran = at the top of the screen

Here, onglet means a tab, especially in a computer or browser context.

So in this sentence:

• Ferme cet onglet = Close that tab

French words often have more than one meaning depending on context. Onglet can literally relate to a nail or tab-like shape, but in technology it commonly means a tab.

Since the sentence also mentions cliquer, icône, and écran, the computer meaning is clearly intended here.

Because French usually omits the subject pronoun in commands.

Instead of saying:

• Tu fermes cet onglet
• Tu cliques sur l’icône bleue

a command becomes:

• Ferme cet onglet
• Clique sur l’icône bleue

This is just how the imperative works in French. The subject is understood.

So the sentence is directly telling someone what to do: Close that tab and click on the blue icon at the top of the screen.

You would use the vous imperative instead of the tu imperative.

Informal singular:

• Ferme cet onglet et clique sur l’icône bleue en haut de l’écran.

Formal singular or plural:

• Fermez cet onglet et cliquez sur l’icône bleue en haut de l’écran.

So:

• Ferme / Clique = informal, one person
• Fermez / Cliquez = formal one person, or more than one person

That distinction is very important in French instructions and polite speech.