Ketten, hárman...

• Mi/ők ketten. – The two of us/them.
• Mi/ők hárman. – The three of us/them.
• Mi/ők négyen. – The four of us/them.
• …

• Ketten vagyunk/vannak. – There are two of us/them.
• Hárman vagyunk/vannak. – There are three of us/them.
• Négyen vagyunk/vannak. – There are four uf us/them.
• …

Note the plural verb forms above. The singular cannot be used:

• Ketten van.
• Hárman van.
• …

Some more examples:

• Ketten egy ellen. – Two people against one.
• Hárman egy ellen. – Three people against one.
• Négyen egy ellen. – Four people against one.

The following are also possible, but less common when referring to people:

• Kettő egy ellen. – Two against one.
• Három egy ellen. – Three against one.
• Négy egy ellen. – Four against one.
• …

As you might have guessed, numerals with the suffix -an/-en refer to people.

Ketten, hárman, négyen refer to two, three, four people, whereas kettő, három, négy… can refer to anything, and usually do not refer to people.

Some more examples follow.

• Mindketten tudjuk/tudják. – We/they both know it.
• Mindhárman tudjuk/tudják. – All three of us/them know it.

Again, note the plural verb forms.The singular cannot be used.

The following forms do not exist. (Starting from four, a definite article is added after mind, see the next section).

• Mindnégyen tudjuk/tudják.
• Mindöten tudjuk/tudják.
• …

The following are also possible, but sound contemptuous when used for people (exactly because they do not normally refer to people):

• Mindkettő tudja. – Both (of them) know it.
• Mindhárom tudja. – All three of them know it.
• …

Note that the singular verb form is used here, as usual.

The following, however, are not possible, because tudjuk – we know can only refer to people:

• Mindkettő tudjuk.
• Mindhárom tudjuk.
• …

• Mind a ketten tudják/tudjuk. – Both of them/us know it.
• Mind a hárman tudják/tudjuk. – All three of them/us know it.
• Mind a négyen tudják/tudjuk. – All four of them/us know it.
• Mind az öten tudják/tudjuk. – All five of them/us know it.
• …
• Mindannyian tudják/tudjuk. – All of them/us know it.

Note that both mindketten and mind a ketten are possible forms as well as mindhárman and mind a hárman. Starting from four, however, a definite article is always added after mind.

• Hányan vagyunk/vannak? – How many are there of us/them?
• Mennyien vagyunk/vannak? – How many are there of us/them?
• Annyian vagyunk/vannak, amennyien akarunk/akarnak. – There are as many of us/them as we/they want.
• Sokan vagyunk/vannak, de nem elegen. – There are many of us/them, but not enough of us/them.

• Ahol ugyanis ketten vagy hárman összegyűlnek az én nevemben, ott vagyok köztük.
• Sokan vannak az elhívottak, de kevesen a választottak.