La bouture reste saine tant que la lumière indirecte suffit.

French usually needs an article before a noun in a normal sentence. So la bouture means the cutting.

Here, la does not necessarily mean a very specific cutting in the way English always does; French often uses the definite article more naturally than English. In a care instruction or description, la bouture can simply mean the cutting being discussed.

Also, bouture is a feminine noun, which is why the article is la.

Rester means to remain or to stay. So reste saine means remains healthy or stays healthy.

That is slightly different from est saine, which would just mean is healthy.

So:

• La bouture est saine = The cutting is healthy.
• La bouture reste saine = The cutting stays/remains healthy.

In this sentence, reste emphasizes that the healthy condition continues as long as the light is sufficient.

Because saine is an adjective agreeing with bouture, which is feminine singular.

The basic masculine form is sain.
The feminine form is saine.

So:

• un plant sain = a healthy plant
• une bouture saine = a healthy cutting

In the sentence, saine agrees with la bouture.

Tant que means as long as in this sentence.

So:

• La bouture reste saine tant que la lumière indirecte suffit.
• The cutting remains healthy as long as indirect light is enough.

It introduces a condition that remains true during a certain time or under a certain circumstance.

Be careful: depending on context, tant que can sometimes also feel like while, but here as long as is the best match.

Because indirecte is an adjective describing the noun lumière.

• la lumière indirecte = indirect light

French adjectives often come after the noun, and this is a normal case of that pattern.

Indirectement is an adverb meaning indirectly, so it would not fit here. The sentence is talking about a type of light, not the manner of an action.

Also, lumière is feminine singular, so the adjective must agree:

• masculine: indirect
• feminine: indirecte

Suffit is the third-person singular present tense of suffire, which means to be enough or to suffice.

The subject is la lumière indirecte, which is singular, so the verb must also be singular:

• la lumière indirecte suffit = indirect light is enough

Conjugation here:

• je suffis
• tu suffis
• il/elle suffit
• nous suffisons
• vous suffisez
• ils/elles suffisent

So suffit is used because the subject is la lumière indirecte.

French, like English, can leave that understood from context.

Here, la lumière indirecte suffit means something like:

• indirect light is enough
• indirect light is sufficient

The idea is clearly enough for the cutting to stay healthy, so French does not need to repeat that.

If you wanted to make it more explicit, French could say things like:

• La lumière indirecte suffit à la bouture.
• La lumière indirecte suffit pour garder la bouture saine.

But the shorter version is very natural when the context already makes the meaning clear.

Both verbs are in the present indicative:

• reste
• suffit

French uses the present tense here because the sentence states a general fact or care guideline.

This is the same idea as in English:

• The cutting remains healthy as long as indirect light is enough.

It is not talking about one single moment in the past or future; it is describing what generally happens.

Not exactly.

• tant que = as long as
• si = if

They are related, but they do not feel the same.

With tant que, the sentence focuses on a condition that continues over time:

• La bouture reste saine tant que la lumière indirecte suffit.
• The cutting stays healthy as long as indirect light is sufficient.

With si, the sentence would sound more like a simple condition:

• La bouture reste saine si la lumière indirecte suffit.
• The cutting stays healthy if indirect light is sufficient.

That version is possible in some contexts, but tant que is better here because it highlights ongoing sufficiency over time.

Yes. You could also say:

Tant que la lumière indirecte suffit, la bouture reste saine.

This means the same thing.

The difference is mainly one of emphasis:

• La bouture reste saine tant que... starts with the result.
• Tant que... la bouture reste saine starts with the condition.

Both are natural. When the tant que clause comes first, a comma is commonly used.

No, the final -t in suffit is normally silent.

A rough pronunciation is:

• suffit ≈ suh-fee

More precisely in IPA: /sy.fi/

Likewise, a few other useful pronunciations in the sentence are:

• bouture = /bu.tyʁ/
• reste = /ʁɛst/
• saine = /sɛn/
• lumière = /ly.mjɛʁ/
• indirecte = /ɛ̃.di.ʁɛkt/

So in normal speech, la lumière indirecte suffit ends with a sound like ... su-fee, not su-feet.