Si le logiciel ne réagit pas, appuie encore une fois sur cette touche.

Appuie is the imperative form, used to give an instruction or command.

Here it is the informal singular command, so it is addressed to one person you would call tu.

With appuyer, the imperative forms are:

• (tu) appuie
• (nous) appuyons
• (vous) appuyez

So:

• appuie = press! / push!
• appuyez = press! when speaking to one person formally or more than one person
• appuyer = the infinitive, to press

A useful detail: in affirmative tu commands, many -er verbs drop the final -s, which is why it is appuie rather than appuies.

French often uses si + present tense for real or possible conditions in the present or future.

So:

• Si le logiciel ne réagit pas... = If the software does not respond...

This is a very normal pattern:

• Si tu as faim, mange. = If you’re hungry, eat.
• Si ça ne marche pas, recommence. = If that doesn’t work, start again.

In this sentence, the structure is:

• Si + present
• then an instruction in the imperative

That combination is very common in manuals, troubleshooting guides, and spoken instructions.

Yes. Logiciel is a masculine noun, so it takes le in the singular:

• le logiciel = the software

In French, every noun has a grammatical gender, and logiciel happens to be masculine.

Related forms:

• un logiciel = a software program / a piece of software
• le logiciel = the software
• les logiciels = software programs

Even though English software is usually uncountable, French logiciel is a normal countable noun.

Réagit comes from réagir, which literally means to react.

In this context, though, English would often say:

• respond
• react
• do anything
• work

So Si le logiciel ne réagit pas means something like:

• If the software doesn’t respond
• If the software doesn’t react
• If the software does nothing

In computer instructions, réagir is very commonly used for a device, program, or system that is not responding to input.

That is the standard French way to make a verb negative.

Here:

• réagit = responds / reacts
• ne réagit pas = does not respond / does not react

French normally places:

• ne before the conjugated verb
• pas after it

So:

• Le logiciel réagit. = The software responds.
• Le logiciel ne réagit pas. = The software does not respond.

In casual spoken French, people often drop ne, but in writing—especially in instructions or formal standard French—you keep both parts.

Here encore une fois means once again or one more time.

That is the natural meaning in this sentence:

• appuie encore une fois = press once again / press one more time

Although encore can sometimes mean still, in this expression it means again.

So do not translate it word for word as still one time. The whole phrase functions as an idiomatic unit:

• encore une fois = again / once more / one more time

French uses appuyer sur for to press on or to press a button/key.

So:

• appuyer sur une touche = to press a key
• appuyer sur un bouton = to press a button

That is just the normal verb-preposition combination in French. English often drops the preposition and simply says press this key, but French usually keeps sur with appuyer.

So:

• appuie sur cette touche = press this key

Even though English does not need on, French does.

Cette touche means this key or this button, depending on context.

• touche often means a key on a keyboard or keypad
• it can sometimes also mean a button on a device

Here, since the sentence is about software and pressing something, this key is probably the most direct translation, but this button could also fit in some contexts.

Also, cette is the feminine singular form of this, because touche is feminine:

• ce for masculine singular
• cette for feminine singular
• ces for plural

This comes from the verb appuyer.

With verbs like appuyer, the y often changes to i before a silent e sound in the ending. That is why you get forms like:

• j’appuie
• tu appuies
• il/elle appuie

The imperative tu form is based on that same stem:

• appuie

So the spelling is not random—it follows the normal conjugation pattern of appuyer.

It is talking to tu, because the command is appuie.

That means the speaker is addressing:

• one person
• in an informal way

If the sentence used vous, it would be:

• Si le logiciel ne réagit pas, appuyez encore une fois sur cette touche.

That version would be used for:

• one person formally
• or several people

In real life, instruction manuals often prefer appuyez, because it sounds more neutral or formal. But appuie is perfectly correct if the instruction is aimed at one person informally, such as in a tutorial, game, or spoken guidance.

Yes. You could also say:

• Appuie encore une fois sur cette touche si le logiciel ne réagit pas.

That means the same thing.

Both orders are grammatical:

• Si le logiciel ne réagit pas, appuie...
• Appuie... si le logiciel ne réagit pas.

Starting with si puts the condition first, which is very natural in instructions because it sets up the situation before giving the action to take.