La prise est difficile à tenir sans magnésie.

Here, prise means a hold or grip, especially in a climbing context. It refers to the part of the wall or rock that you grab with your hand.

This is a good example of a French word whose meaning depends a lot on context. In other situations, prise can also mean things like:

• socket / outlet → prise électrique
• taking / capture
• shot or take in film-making

But in La prise est difficile à tenir, it means the hold.

La prise means the hold rather than a hold.

French often uses the definite article (le / la / les) where English might or might not use the, depending on context. Here, la prise probably refers to a specific hold already known from the situation:

• La prise est difficile à tenir. = The hold is hard to keep/hold.
• Une prise est difficile à tenir. = A hold is hard to keep/hold.
  This sounds more general or like you are introducing it for the first time.

So la suggests a particular hold being discussed or pointed out.

This is a very common question.

In French, adjective + à + infinitive is often used when the noun is the thing that undergoes the action:

• La prise est difficile à tenir.
• literally: The hold is difficult to hold.
• more natural English: The hold is hard to keep/hold onto.

This structure is very common:

• facile à comprendre = easy to understand
• difficile à faire = hard to do
• agréable à regarder = pleasant to look at

By contrast, difficile de + infinitive is more often used in more general statements:

• Il est difficile de tenir cette prise. = It is difficult to hold this hold.

So both patterns exist, but they are used differently:

• La prise est difficile à tenir. → focus on the hold
• Il est difficile de tenir cette prise. → focus on the action of holding it

Here, tenir means to hold, to keep holding, or to maintain your grip on something.

That is important because tenir has several meanings in French, such as:

• to hold
• to keep
• to last
• to stand / remain
• to be attached to / care about in some expressions

In a climbing sentence like this, tenir une prise means to hold onto a hold or to keep your grip on it.

In this context, magnésie means chalk, the white powder climbers and gymnasts use on their hands to improve grip.

A learner might be confused because magnésie looks related to magnesium, but in sports vocabulary it usually refers to climbing/gym chalk, not the chemical element in a broad scientific sense.

So:

• sans magnésie = without chalk

After sans, French often uses a noun without an article when speaking in a general sense.

So:

• sans magnésie = without chalk
• sans sucre = without sugar
• sans eau = without water
• sans argent = without money

This is the normal pattern when you mean the substance or thing generally, not a specific one.

You would use an article only if you meant something specific:

• sans la magnésie que tu m’as prêtée = without the chalk you lent me

But in your sentence, sans magnésie just means without any chalk / without chalk in general.

Good observation. Prise is feminine, but difficile has the same form in the masculine and feminine singular.

So:

• un exercice difficile
• une prise difficile

The adjective difficile does agree grammatically, but you do not see a spelling change in the singular.

You only clearly see a different form in the plural:

• une prise difficile
• des prises difficiles

Yes, absolutely. In natural English, that is often the best translation here.

Depending on context, you might translate:

• La prise est difficile à tenir. as
  The hold is hard to hold.
  The hold is hard to keep.
  The hold is hard to hold onto.

The most natural English version in a climbing context is often hard to hold onto or hard to keep hold of.

Yes. The pattern noun + être + adjective + à + infinitive is very common and useful.

Examples:

• Ce livre est facile à lire. = This book is easy to read.
• Cette porte est difficile à ouvrir. = This door is hard to open.
• Le pain est bon à manger. = The bread is good to eat.
• La prise est difficile à tenir. = The hold is hard to hold onto.

English speakers should notice that French often expresses this idea very directly with à + infinitive.

Yes, it could, but it is a little different in tone.

• difficile à tenir = difficult/hard to hold
• dure à tenir = hard/tough to hold

Difficile is more neutral and standard.
Dure can sound a bit more informal, vivid, or physical.

In climbing, both could be understood, but difficile à tenir is a very safe and standard choice.

A rough pronunciation is:

La prise est difficile à tenir sans magnésie
→ lah preez eh dee-fee-seel ah tuh-neer sahn ma-nay-zee

A few useful pronunciation notes:

• prise sounds roughly like preez
• est is pronounced eh
• difficile = dee-fee-seel
• tenir = tuh-neer
• sans is nasal: sahn
• magnésie = mag-nay-zee

Also, in natural speech, French flows smoothly, so the sentence may sound more connected than the word-by-word breakdown suggests.