Using verb infinitives in a sentence.

[bricks]

Hello.

I know that you use the verb infinitive after a conjugation. For example, Puedo hablar contigo?

But I see other sentences where the infinitive is used. I can't give an example right now, sorry.

Actually, the song como poder saber si te amo by leo dan. Why not Puedo instead poder?

Thank you.

[Perikles]

Originally Posted by bricks

I know that you use the verb infinitive after a conjugation. For example, Puedo hablar contigo?.

What you are talking of here are known as modal auxiliary verbs, and the use is the same in English:

I have (modal) to eat (infinitive)
I want (modal) to cry (infinitive)
I ought (modal) to go (infinitive)

The verbs can and must take a shortened infinitive

I can (modal) see (infinitive) you
I must (modal) go (infinitive)
How can (modal) I know? (short infinitive)

Originally Posted by bricks

But I see other sentences where the infinitive is used. ..

Actually, the song como poder saber si te amo by leo dan. Why not Puedo instead poder?

You should say: cómo puedo saber ... for it to be correct, but the lyrics of a song are not always grammatical. [How can (modal) I know? (short infinitive)]

The infinitive is also used in Spanish where English uses a gerund: I like walking etc. But it's too much info for one post. Give me another example, and I'll try and explain.

[bobjenkins]

Es difícil explicar sin ejemplos , por lo menos para mi

[irmamar]

This is what is called "perífrasis verbal", in which two verbs are joined together. The second verb can be an infinitive, present participle, and a past participle.

Infinitive can be joined to the first verb with a preposition or relative pronoun (ir a pasear, tener que ir, etc.). Modal verbs, as Perikles said, such as saber, poder, querer, deber, soler, and those which have a similar meaning can be joined to the first verb without a preposition (poder saber, querer decir, desear hablar, soler pasear, saber callar, etc.). Logically, you can conjugate the first of these verbs:

Quisiera poder saber todo lo que pasa en el mundo.
Nadie puede saber todo lo que pasa en el mundo.

[Perikles]

Originally Posted by bobjenkins

Es difícil explicar sin ejemplos ,

[bobjenkins]

Originally Posted by bobjenkins

Es difícil explicar sin ejemplos

Originally Posted by irmamar

This is what is called "perífrasis verbal", in which two verbs are joined together. The second verb can be an infinitive, present participle, and a past participle.

Infinitive can be joined to the first verb with a preposition or relative pronoun (ir a pasear, tener que ir, etc.). Modal verbs, as Perikles said, such as saber, poder, querer, deber, soler, and those which have a similar meaning can be joined to the first verb without a preposition (poder saber, querer decir, desear hablar, soler pasear, saber callar, etc.). Logically, you can conjugate the first of these verbs:

Quisiera poder saber todo lo que pasa en el mundo.
Nadie puede saber todo lo que pasa en el mundo.

A menos que eres Irmamar

[irmamar]

Originally Posted by bobjenkins

A menos que eres Irmamar

A menos que hables español

A menos que seas... (subjuntivo)

[bobjenkins]

Originally Posted by irmamar

A menos que hables español

A menos que seas... (subjuntivo)

el subjuntivo me aterriza

[irmamar]

Originally Posted by bobjenkins

el subjuntivo me aterriza

¿Dónde te aterriza?

Aterrizar: to land
Aterrorizar: to terrify

[bobjenkins]

Originally Posted by irmamar

¿Dónde te aterriza?

Aterrizar: to land
Aterrorizar: to terrify

Ten cuidado bob está al trabajo hacer los errores

[irmamar]

Originally Posted by bobjenkins

Ten cuidado bob está al trabajo hacer los errores

Ten cuidado. Bob está trabajando (perífrasis ) haciendo los errores.

[bricks]

Originally Posted by irmamar

Infinitive can be joined to the first verb with a preposition or relative pronoun (ir a pasear, tener que ir, etc.). Modal verbs, as Perikles said, such as saber, poder, querer, deber, soler, and those which have a similar meaning can be joined to the first verb without a preposition (poder saber, querer decir, desear hablar, soler pasear, saber callar, etc.). Logically, you can conjugate the first of these verbs:

So it is a matter of choice whether I conjugate the first verb of just use two modals?

I have an example now, actually:

When saying "cierra la boca", I've also seen "cerrar la boca". Why is this acceptable and what is the difference. I know they mean the same thing, but why choose one over the over??

In comparison, "besa mi culo" is correct, but "besar mi culo" isn't.

I really don't get it.

[Perikles]

Originally Posted by bricks

I have an example now, actually:

When saying "cierra la boca", I've also seen "cerrar la boca". Why is this acceptable and what is the difference. I know they mean the same thing, but why choose one over the over??

In comparison, "besa mi culo" is correct, but "besar mi culo" isn't.

I really don't get it.

You may be confusing two forms of the imperative (commands). The infinitive is one possibility, though very unlikely in the two examples you cite. I'm not sure where you are coming from.

[irmamar]

You can use infinitive in a sentence. And,as Perikles said, you are using the imperative form. You could threaten or give an advice to somebody using an infinitive in your sentences:

Vas a cerrar la boca.
Vas a besarme el culo (sorry , that was the example).
Tienes que estudiar más.
No puedes ir allí.
etc.

[bricks]

Basically I will put my question simply like this.

When do I say "cierra la boca", and when do I say "cerrar la boca" ?

[Perikles]

Originally Posted by bricks

Basically I will put my question simply like this.

When do I say "cierra la boca", and when do I say "cerrar la boca" ?

The first is telling someone to shut up. The second is not a sentence, just a concept, unless you understand cerrar as an imperative, which is really unlikely. So use the first one.

[irmamar]

Originally Posted by Perikles

The first is telling someone to shut up. The second is not a sentence, just a concept, unless you understand cerrar as an imperative, which is really unlikely. So use the first one.

I agree

Now I remember that sometimes, some people use "infinitive" instead "imperative" with the second person plural:

Instead of saying: "cerrad la boca", they say: "cerrar la boca".

I should add that it's used with "vosotros", of course.

[bobjenkins]

Originally Posted by irmamar

Ten cuidado. Bob está trabajando (perífrasis ) haciendo los errores.

As I said

muchas gracias!

[irmamar]

Originally Posted by bobjenkins

As I said

¡muchas gracias!

No hay de qué.

[bricks]

Thank you Perikles. I always thought that the infinitive was used when you want to tell someone something, or command them, or threaten them. I guess you're saying it is not?

Originally Posted by irmamar

I agree

Now I remember that sometimes, some people use "infinitive" instead "imperative" with the second person plural:

Instead of saying: "cerrad la boca", they say: "cerrar la boca".

I should add that it's used with "vosotros", of course.

I'm not asking about vosotros. Why don't you just answer what I ask, or not at all. Can't get much simpler than that for you.