Learn Hardcore German: Wenn du Zeit hast, kannst du mir deinen Pullover für den Ausflug ausleihen? - If you have time, can you lend me your sweater for the trip?

Wenn du Zeit hast is a subordinate clause introduced by wenn. In German subordinate clauses, the conjugated verb goes to the very end of the clause.

Main clause: Du hast Zeit. (verb in 2nd position)
Subordinate clause: Wenn du Zeit hast, … (verb at the end)

So hast is at the end because wenn makes this a subordinate (dependent) clause.

Does wenn here mean if or when, and why isn’t it als?

In German, wenn can mean both:

if (conditional)
when/whenever (repeated or general time)

In this sentence, it’s conditional: If you have time…

Als is used for when in the sense of at the time when referring to a single event in the past:

Als ich jung war, wohnte ich in Berlin. – When I was young, I lived in Berlin.

Here we’re not talking about a specific past event, but a condition, so wenn is correct.

Why is there a comma after Wenn du Zeit hast?

German always uses a comma to separate a subordinate clause from the main clause.

Subordinate clause: Wenn du Zeit hast
Main clause: kannst du mir deinen Pullover … ausleihen?

The comma marks the boundary between the two clauses. This is a fixed rule in German punctuation.

Why is the verb ausleihen at the end of kannst du mir deinen Pullover … ausleihen?

There are two things going on:

Modal verb construction:
- kannst is the conjugated modal verb (2nd position)
- the main verb ausleihen stays in the infinitive and goes to the end of the clause
Pattern: [modal, conjugated] + … + [main verb in infinitive at the end]
Example: Ich will heute meinen Pullover ausleihen.
Ausleihen is a separable verb (aus- + leihen).
- With a modal, the verb stays in one piece: ausleihen.
- Without a modal, it would split:
  - Du leihst mir deinen Pullover aus.

So the question form with a modal is:
kannst du … ausleihen? – conjugated modal early, infinitive at the end.

Why is it mir and not mich?

Mir is dative; mich is accusative.

The verb (aus)leihen here has:

a direct object (what is being lent) → accusative
- deinen Pullover
an indirect object (to whom it is lent) → dative
- mir

So:

Kannst du mir (dative) deinen Pullover (accusative) ausleihen?
English: Can you lend *me your sweater?*

Using mich (accusative) here would be ungrammatical.

Why is it deinen Pullover and not just dein Pullover?

Pullover is masculine: der Pullover.
Here it is the direct object of the verb ausleihen → accusative case.

Masculine dein- in accusative takes -en:

Nominative: dein Pullover – Dein Pullover ist schön.
Accusative: deinen Pullover – Ich mag deinen Pullover.

Because we are lending your sweater → direct object, accusative → deinen Pullover.

Why is it für den Ausflug and not für dem Ausflug?

The preposition für always takes the accusative case.

der Ausflug (nominative)
den Ausflug (accusative)
dem Ausflug would be dative, but dative is not allowed after für.

So you must say:

für den Ausflug – for the trip/excursion

This is a general rule: für + accusative (für den, für die, für das, für die [Plural]).

What is the difference between leihen and ausleihen here?

In everyday use:

jemandem etwas leihen
jemandem etwas ausleihen

are often used interchangeably and both mean to lend someone something.

Very roughly in nuance:

leihen can mean lend or borrow depending on context (especially in colloquial speech).
ausleihen often emphasizes giving something out on loan, sometimes more clearly on the lending side.

But in this sentence, using leihen instead would be completely natural:

… kannst du mir deinen Pullover für den Ausflug leihen? – still fine.

Is Kannst du mir deinen Pullover … ausleihen? a yes/no question even though it starts with Wenn du Zeit hast?

Yes. The real main clause is:

kannst du mir deinen Pullover für den Ausflug ausleihen?

and here the verb kannst comes before the subject du, which is the typical yes/no question word order in German:

Statement: Du kannst mir deinen Pullover ausleihen.
Question: Kannst du mir deinen Pullover ausleihen?

The wenn-clause at the beginning is just extra information placed before the main clause. It doesn’t change the fact that the main clause is a yes/no question, so you still use a question mark.

Can I also say Kannst du mir deinen Pullover für den Ausflug ausleihen, wenn du Zeit hast??

Yes, that’s perfectly correct and means the same thing.

German allows you to put the wenn-clause either:

at the beginning:
- Wenn du Zeit hast, kannst du mir … ausleihen?
or at the end:
- Kannst du mir … ausleihen, wenn du Zeit hast?

The meaning and grammar stay the same. The version with wenn at the beginning slightly emphasizes the condition first.

Is this present tense used for the future, like in English “If you have time tomorrow…”?

Yes. German very often uses present tense for future meanings in conditional sentences, especially with wenn:

Wenn du morgen Zeit hast, können wir ins Kino gehen.
→ If you have time tomorrow, we can go to the cinema.

So Wenn du Zeit hast… can easily refer to time in the near or future context; you don’t need a special future tense here.

How would I make this sentence formal with Sie?

Formal you in German is Sie, and the verb and possessive change to the 3rd person plural form:

Wenn Sie Zeit haben, können Sie mir Ihren Pullover für den Ausflug ausleihen?

Changes:

du hast → Sie haben
kannst du → können Sie
deinen Pullover → Ihren Pullover (possessive for Sie, accusative masculine)

Also, Sie and Ihr/Ihren must be capitalized in the formal form.

Could I say Wenn du Zeit hättest, könntest du mir deinen Pullover … ausleihen? and what’s the difference?

Yes, and it changes the nuance.

Original (realistic, neutral request):

Wenn du Zeit hast, kannst du mir deinen Pullover … ausleihen?
→ If you have time, can you lend me your sweater?

With hättest/könntest (Konjunktiv II), it becomes more hypothetical/polite/less direct:

Wenn du Zeit hättest, könntest du mir deinen Pullover … ausleihen?
→ If you had time, could you lend me your sweater?

This is similar to the English “could you / would you” form, which often sounds more polite and less like a direct request.