Quotiens forfex movetur, totiens capillus cadit.

This is a very common Latin correlative pair.

• quotiens = as often as / whenever / every time that
• totiens = so often / that many times / each time

So Quotiens forfex movetur, totiens capillus cadit means something like:

• Every time the scissors move, a hair falls
• As often as the scissors are moved, so often a hair falls

English usually does not keep the pair as neatly as Latin does, but Latin likes this balanced structure.

Because Latin and English do not always divide things up the same way.

In English, scissors is normally a plural-looking word even when it refers to one tool.
In Latin, forfex is a singular noun meaning a pair of scissors / shears.

So:

• forfex movetur = the scissors are moved

This is perfectly normal Latin. You do not need a plural verb just because English uses scissors.

Forfex is nominative singular because it is the subject of movetur.

In the clause:

• forfex movetur

the thing grammatically doing or receiving the action is forfex. Since the verb is passive, the scissors are the subject of the passive verb:

• the scissors are moved

So forfex is nominative.

Movetur is the present passive indicative, third person singular, from moveo (move).

So literally it means:

• is moved

Latin often uses the passive when the agent is not important or is obvious from context. Here the sentence focuses on the repeated action of the scissors, not on the person using them.

So:

• forfex movetur = the scissors are moved

In smoother English, you might simply think:

• the scissors move

But grammatically, Latin is using a passive form.

Yes. For example, Latin could say something like:

• Quotiens tonsor forficem movet, totiens capillus cadit.
• Every time the barber moves the scissors, a hair falls.

That version names the agent (tonsor, barber) and uses the active verb movet.

The original sentence leaves the agent unstated and keeps the focus on the general repeated event.

Movetur breaks down like this:

• verb: moveo, movere = to move
• tense: present
• voice: passive
• mood: indicative
• person/number: 3rd person singular

So it means:

• he/she/it is moved

Here the it is forfex.

Yes, and that is one of the differences between Latin and English.

Capillus means a hair (an individual strand), though in some contexts Latin can also use singular or plural more generally depending on what is being emphasized.

Here the singular makes good sense:

• capillus cadit = a hair falls

That suggests the cutting action in an individual, repeated way: each movement of the scissors causes a hair to fall.

If Latin wanted to emphasize multiple hairs, it could use a plural such as capilli, but the singular here is very natural.

Capillus is nominative singular, because it is the subject of cadit.

In the second clause:

• capillus cadit

the hair is the thing that falls, so it is the subject, and subjects are normally in the nominative.

Cadit comes from cado, cadere, meaning to fall.

Its form is:

• present
• active
• indicative
• 3rd person singular

So it means:

• he/she/it falls

Here it means:

• a hair falls

The present tense here expresses a general truth or a habitual/repeated action.

The sentence is not mainly about one specific moment in the past or future. Instead, it describes what happens whenever this situation occurs:

• when the scissors are moved, a hair falls

This kind of present tense is very common in Latin, just as English often uses the present for general statements:

• When you heat water enough, it boils
• Every time the scissors move, a hair falls

Grammatically, it presents the idea that way, yes: one repeated action matched with one repeated result.

But in practice, such sentences often express a general pattern rather than a mathematically exact count. The point is the repeated relationship:

• movement of the scissors
• falling of hair

So the sentence is more about the regular connection between the two actions than about strict arithmetic precision.

Latin word order is flexible, but important linking words are often placed prominently.

Here the structure is very neat:

• Quotiens ... = as often as / whenever
• totiens ... = so often / each time

Putting quotiens first immediately signals that a subordinate clause is beginning, and totiens then answers it in the main clause. This creates a balanced, almost formula-like pattern.

Yes, Latin word order is flexible, so other arrangements are possible. But this order is especially clear and elegant because it highlights the correlation:

• quotiens ... totiens

If you moved words around, the sentence could still be grammatical, but it might lose some of that neat balance.

Forfex is feminine.

So if you ever saw an adjective agreeing with it, that adjective would normally be in the feminine form.

In this sentence, there is no adjective with forfex, so you do not directly see the gender in the wording of the sentence itself.

In this sentence, forfex means a cutting tool such as scissors or shears.

Exactly which English word you choose depends on context:

• scissors if you imagine ordinary hair-cutting scissors
• shears if you imagine a larger cutting tool

For a learner, scissors is the most natural translation here.

Classical Latin has no articles like English the and a/an.

So:

• forfex can mean the scissors or a pair of scissors, depending on context
• capillus can mean a hair or sometimes the hair, depending on context

English must choose an article when translating, but Latin leaves that to context.

A few natural possibilities are:

• Every time the scissors move, a hair falls.
• Whenever the scissors are moved, a hair falls.
• As often as the scissors are moved, a hair falls.

The first is probably the most natural everyday English version. The second is closer to the Latin passive movetur.