Learn Hardcore French: Les problèmes techniques arrivent surtout quand le Wi‑Fi est faible. - Technical problems happen mainly when the Wi‑Fi is weak.

In French, it’s very common to talk about this kind of thing in the plural when you mean “problems in general” or “technical issues” as a category.
So les problèmes techniques is best translated as “technical problems / technical issues” rather than “the technical problem.”

You could say le problème technique if you’re talking about one specific, identified problem, but in a general statement like this, French naturally uses the plural.

Why is the adjective after the noun: problèmes techniques and not techniques problèmes?

Most French adjectives come after the noun, especially when they describe type or category, like problèmes techniques, questions financières, difficultés linguistiques.

Some shorter, very common adjectives (like grand, petit, beau, bon, mauvais, jeune, vieux, nouveau) often come before the noun, but technique does not belong to that group.
So problèmes techniques is the normal word order.

Why use arrivent here? Could I say se passent or se produisent instead?

arriver (used like “to happen”) is very common and neutral:
- Les problèmes techniques arrivent… = “Technical problems happen…”
se produire is a bit more formal or technical:
- Les problèmes techniques se produisent surtout… is perfectly correct, just a bit more “written” or serious in tone.
se passer also means “to happen,” but is used a bit more for events or situations in general:
- Qu’est‑ce qui se passe ? = “What’s happening?”

In your sentence, arrivent is the most natural everyday choice, but se produisent would also work. Se passent would be understood, but it’s less idiomatic with problèmes techniques; natives are more likely to say arrivent or se produisent with “problèmes”.

What exactly does surtout mean here? Is it “especially” or “mostly”?

In this sentence, surtout can be understood as “mainly / mostly / especially.”

Les problèmes techniques arrivent surtout quand…
→ “Technical problems mostly happen when…”
It doesn’t mean “above all, don’t forget” here, but rather indicates the most frequent situation where problems occur.

So both “mostly” and “especially” are reasonable translations in this context.

Why is surtout placed before quand? Could I move it?

The position arrivent surtout quand… is the most natural and common: the adverb surtout comes after the verb and before the quand-clause.

You could occasionally see:

Les problèmes techniques arrivent, surtout quand le Wi‑Fi est faible.

with a comma; this visually separates surtout a bit more and gives it a slight emphasis.

Forms like Les problèmes techniques surtout arrivent… sound unnatural; surtout doesn’t normally go between subject and verb here.

Why is it quand and not lorsque? Are they interchangeable?

In this sentence, quand and lorsque are virtually interchangeable:

Les problèmes techniques arrivent surtout quand le Wi‑Fi est faible.
Les problèmes techniques arrivent surtout lorsque le Wi‑Fi est faible.

Both are correct.
lorsque is often a bit more formal or written, while quand is more neutral and very common in speech. The meaning here doesn’t change.

Why do we say le Wi‑Fi and not just Wi‑Fi without an article?

In French, nouns normally need an article, even when they are technical terms or brand‑like words.

Wi‑Fi is treated as a masculine noun, so you get:

le Wi‑Fi = “the Wi‑Fi connection / the Wi‑Fi signal”

You might hear people casually say things like j’ai pas de Wi‑Fi (no article because of de), but when it’s the subject of the sentence in a neutral form, French prefers le Wi‑Fi rather than bare Wi‑Fi.

Is Wi‑Fi masculine or feminine in French, and how do we know?

In modern French, Wi‑Fi is normally masculine:

le Wi‑Fi est faible
un réseau Wi‑Fi, un Wi‑Fi rapide

The gender is mainly established by usage: dictionaries and common speech treat it as masculine. There isn’t always a logical rule; many loanwords simply get a gender by convention.

Why is it est faible (“is weak”) and not something like est bas or marche mal?

In this context:

faible is the normal adjective for a weak signal / weak power:
- un signal faible, un son faible, une lumière faible
- le Wi‑Fi est faible = “the Wi‑Fi signal is weak.”
bas usually refers to low level/height (e.g. un niveau bas, une chaise basse), less natural with a signal.
marche mal (“works badly”) is possible:
- Les problèmes techniques arrivent surtout quand le Wi‑Fi marche mal.
  This shifts the idea from “the signal is weak” to “the Wi‑Fi isn’t working well,” which is a bit broader than just signal strength.

So est faible focuses specifically on signal strength, which fits very well here.

Why is the verb in the present: arrivent, est? Could we use a future tense?

French uses the present tense here to express a general truth / habitual situation, just like English does:

“Technical problems happen mostly when the Wi‑Fi is weak.”

You could use the future if you were talking about a specific future situation:

Les problèmes techniques arriveront surtout quand le Wi‑Fi sera faible.
→ “Technical problems will mostly occur when the Wi‑Fi is weak.”

But for a general statement about how things usually go, the present is the natural tense.

Could we say Les problèmes techniques surviennent surtout quand le Wi‑Fi est faible? What’s the difference with arrivent?

Yes, that sentence is correct:

survenir also means “to occur / to arise / to crop up.”

Differences:

arriver is more common and neutral, very frequent in everyday language.
survenir sounds more formal or technical, often used in written language, reports, or more serious contexts:
- Des complications peuvent survenir.

Meaning-wise, they’re very close here; it’s mainly a difference in tone/register.

Could we replace quand le Wi‑Fi est faible with avec un Wi‑Fi faible?

You could say:

Les problèmes techniques arrivent surtout avec un Wi‑Fi faible.

This is grammatically correct and understandable, but it sounds a bit more written and slightly less natural than the original.

Using quand + verb (quand le Wi‑Fi est faible) is the most natural way to express a condition of time/circumstance in everyday French: “when the Wi‑Fi is weak.”