Un technicien vérifie les câbles électriques pour la sécurité de tous.

In French, un is an indefinite article (a technician), while le is a definite article (the technician).

• Un technicien suggests any technician, not a specific one the listener already knows about.
• Le technicien would refer to a particular technician already identified in the context (for example, “the technician we talked about earlier”).

Here, the sentence is describing a general situation, so un technicien (a technician) is more natural.

Yes. The feminine form of un technicien is une technicienne.

So the sentence would become:

• Une technicienne vérifie les câbles électriques pour la sécurité de tous.

Notice the changes:

• un → une for feminine singular.
• technicien → technicienne for a female technician.

In this sentence, technicien is singular, so the verb must be conjugated in the third person singular of the present tense: il/elle vérifie.

• Un technicien vérifie = A technician checks → singular subject.
• Des techniciens vérifient = Technicians check → plural subject, so the verb becomes vérifient.

The English word “technician” can refer to one person or many depending on context, but in French the article un clearly shows that it’s just one technician, so the verb is singular.

French présent de l’indicatif covers several English present uses:

• He checks (habit, routine)
• He is checking (action happening now)
• He does check (emphatic)

So Un technicien vérifie les câbles électriques can mean:

• A technician checks the electric cables (general or routine action), or
• A technician is checking the electric cables (right now), depending on the context.

If you really want to insist that it’s happening right now, you can say:

• Un technicien est en train de vérifier les câbles électriques. (literally “is in the middle of checking”)

• les câbles électriques = the electric cables (a specific, known set of cables)
• des câbles électriques = (some) electric cables (an unspecified number of them)

Here, it sounds like the technician is checking all the relevant cables in a system or place, so French naturally uses les to mean “those particular cables” that belong to that installation or context.

If you said des câbles électriques, it would sound more like “some electric cables” without specifying which, which is weaker and less natural in this kind of safety context.

In French, most adjectives come after the noun, unlike in English:

• English: electric cables
• French: des câbles électriques

The adjective électrique (electric) is one of the adjectives that normally follows the noun.

Some adjectives come before the noun (often very common, short ones like grand, petit, beau, vieux, bon, mauvais), but électrique is not one of those. So électriques câbles would be incorrect.

Both câble électrique and câbles électriques are grammatically correct, but they mean different things:

• un câble électrique = one electric cable
• des câbles électriques / les câbles électriques = (some / the) electric cables (more than one)

In the sentence, there are multiple cables being checked, so both the noun and the adjective are put in the plural:

• les câbles électriques → -s on both câbles and électriques for plural agreement.

This is why you see câbles électriques (plural) instead of câble électrique (singular).

Literally, pour la sécurité de tous means “for the safety of everyone”.

• pour here expresses purpose / goal:
  
  • Il vérifie les câbles pour la sécurité de tous.
    → He checks the cables in order to ensure everyone’s safety.

You could also phrase it with a verb:

• … pour assurer la sécurité de tous. = in order to ensure the safety of everyone.

So pour is like “for” / “in order to” when expressing purpose.

Both mean roughly “of everyone”, but they differ a bit in style:

• de tous is shorter and a bit more formal or neutral. It fits well in written language, instructions, safety messages, etc.
• de tout le monde is more conversational and very common in speech.

So:

• pour la sécurité de tous sounds like something you might see in a notice, rule, or formal sentence.
• pour la sécurité de tout le monde is fine, just a little more informal, everyday style.

Yes, you can say pour la sécurité de chacun, and it is grammatically correct.

Nuances:

• de tous = of everyone (as a group, collectively)
• de chacun = of each person (emphasizes individual safety)

So:

• pour la sécurité de tous → focus on the safety of the group.
• pour la sécurité de chacun → subtly emphasizes that every single person’s safety is taken into account.

Both are natural; the original is the most standard neutral phrasing.

Key pronunciation points:

• Un technicien → [œ̃ tɛk.nis.jɛ̃]

  • Final -n in un is nasalized, not pronounced as an [n].
  • technicien ends with a nasal sound -ien → [jɛ̃].

• vérifie → [ve.ʁi.fi]

  • Final -e is pronounced here because it’s part of the 3rd person singular form, three syllables: vé-ri-fie.

• les câbles électriques → [le kabl‿e.lɛk.tʁik]

  • Final -s of les is linked to the vowel of électriques: les‿électriques → [lez‿e.lɛk.tʁik].
  • Final -s in câbles is silent.

• pour la sécurité de tous → [puʁ la se.ky.ʁi.te də tus]

  • Final -s of tous is pronounced [s] here because it stands alone at the end of the phrase.

Important liaison:

• Say les‿électriques with a smooth link: [lez‿e-], not [le e-].

You can use other verbs, but there are small differences in nuance:

• vérifier = to check, to verify that something is correct/safe/working.
  
  • Un technicien vérifie les câbles électriques.
• contrôler = to check, inspect, often in a more systematic or official way.
  
  • Un technicien contrôle les câbles électriques. (also very natural)
• examiner = to examine closely, look at in detail (more about careful observation).
  
  • Un technicien examine les câbles électriques.

In a safety context, vérifier and contrôler are the most common choices. Examiner can be used, but it emphasizes the careful looking rather than the idea of testing/checking they are safe.