هذا يكفي.

• هذا = this. It is a demonstrative pronoun in the masculine singular.
• يكفي = is enough / suffices. It is a verb in the imperfect (non-past) form, 3rd person masculine singular, from the verb كَفَى / يَكْفِي.

So the sentence is literally something like This suffices or This is enough.

Because هذا is the masculine singular form of this in Modern Standard Arabic.

• هذا = this (masculine)
• هذه = this (feminine)

In هذا يكفي, the speaker is referring to something treated as masculine singular.

If the thing were feminine, you would normally say:

• هذه تكفي = This is enough (for a feminine thing)

The verb agrees with the subject in gender and number here.

Since هذا is masculine singular, the verb appears as يكفي, which is also 3rd person masculine singular.

If the subject were feminine, you would usually get:

• هذه تكفي

So the masculine form of the demonstrative and the verb match each other.

The base verb is كَفَى in the past tense, and its imperfect form is يَكْفِي.

Its core meaning is:

• to be enough
• to suffice
• sometimes to satisfy or to spare someone from needing more, depending on context

Examples:

• يكفي هذا = This is enough
• هذا يكفي = This is enough
• يكفيني هذا = This is enough for me

Arabic often does not use a separate present-tense verb meaning is / am / are in simple nominal sentences.

However, in هذا يكفي, the sentence already contains a real verb: يكفي = suffices / is enough.

So this is not a case of a missing is. The idea of is enough is already built into يكفي.

That is why Arabic does not need an extra word here.

Yes. هذا كافٍ is also possible.

There is a useful difference:

• هذا يكفي = This is enough / This will do
  This uses a verb and often sounds a bit more dynamic or practical.
• هذا كافٍ = This is sufficient / This is enough
  This uses the active participle كافٍ, which behaves more like an adjective.

Both are correct, but هذا يكفي is very common in everyday use when someone wants to say That’s enough or This will do.

Yes, يكفي هذا is also possible.

Both mean roughly the same thing:

• هذا يكفي
• يكفي هذا

The difference is mainly one of style or emphasis.

• هذا يكفي puts this first, which can sound like This is enough
• يكفي هذا puts the verb first, which can sound a little more verbal: This suffices / This will do

In many contexts, both are natural.

It is pronounced approximately:

hādhā yakfī

A rough breakdown:

• هذا = hā-dhā
• يكفي = yak-fī

Notes:

• The ذ sound is like the th in this
• The final -ī in يكفي is a long ee sound

So an English speaker can think of it roughly as: HAA-thaa yak-FEE

Formally, يكفي is the imperfect form. In Arabic, the imperfect can express:

• present
• general truth
• near future, depending on context

So هذا يكفي usually means:

• This is enough
• This suffices
• This will do

Without extra context, it is most naturally understood as a present-time statement.

In normal written Arabic, short case endings are often not written, and in everyday pronunciation they are often not pronounced in pause.

So you usually see:

• هذا يكفي

rather than a fully vocalized form with all endings.

Also, هذا is a special form that does not behave exactly like a regular noun with simple visible case endings.

For learners, the important thing is to recognize the sentence as a very common natural expression, even if not every grammatical ending is shown.

Yes, depending on context.

Literally, هذا means this, but in actual use هذا يكفي can function like English:

• This is enough
• That’s enough
• This will do

For example, if someone offers you more food and you want to stop, هذا يكفي can naturally mean That’s enough in the situation, even though the literal word is this.

A very common way is:

هذا يكفيني

Here, -ني means me, so:

• يكفي = is enough
• يكفيني = is enough for me

You may also see:

• هذا يكفي لي

Both are understandable, but يكفيني is very natural and compact.