qǐng xuǎnzé xǐyīchéngxù.

请 makes the command more polite. In a sentence like 请选择洗衣程序, it works a lot like please in English.

So:

• 选择洗衣程序 = select the washing program
• 请选择洗衣程序 = please select the washing program

In instructions on machines, screens, and signs, 请 is very common. It softens the tone without changing the basic meaning.

Mandarin often leaves out subjects when they are obvious from context.

On a washing machine screen, the person reading the message is obviously the one who should do the action, so 你 is unnecessary.

A fuller version would be:

• 请你选择洗衣程序。

But this sounds a bit more explicit than what you usually see on a machine. The shorter 请选择洗衣程序。 is more natural for interface language and instructions.

A good breakdown is:

• 请 = please
• 选择 = to choose / select
• 洗衣程序 = washing program / wash cycle

So the structure is:

• 请 + 选择 + 洗衣程序

It is helpful to treat 洗衣程序 as one noun phrase:

• 洗衣 = washing clothes / laundry
• 程序 = procedure, program, cycle

Together, 洗衣程序 means the washing machine’s program or cycle.

Here, 选择 is a verb, meaning to choose or to select.

Examples:

• 请选择一个选项。 = Please select an option.
• 我选择这个。 = I choose this.

But 选择 can also be a noun in other contexts, meaning choice or selection:

• 这是一个很好的选择。 = This is a very good choice.

In your sentence, it is clearly a verb because it is telling the user to do something.

Yes, you could. 选 is a shorter form of 选择, and in many situations it means the same thing.

Compare:

• 请选择洗衣程序。 = slightly more formal / standard
• 请选洗衣程序。 = shorter, more compact

On buttons, menus, and small screens, shorter wording is common. But 选择 often sounds a little more polished and is very common in written instructions.

Yes. In this context, 程序 means something like program, cycle, or procedure.

For washing machines, 洗衣程序 refers to the washing mode or cycle, such as:

• quick wash
• delicate
• heavy wash
• cotton
• rinse only

So although 程序 can mean procedure in some contexts, on an appliance it is often best understood as program or cycle.

Mandarin often puts nouns together directly to form compound nouns, especially in technical or everyday product language.

So:

• 洗衣程序 = laundry-washing program / washing program

Using 的 is usually unnecessary here. In fact, 洗衣程序 sounds more natural and compact.

Compare:

• 洗衣程序 = normal, standard label
• 洗衣的程序 = understandable, but less natural for a machine interface

This kind of compact noun-building is very common in Mandarin.

选择 is pronounced xuǎn zé.

Tone pattern:

• 选 xuǎn = 3rd tone
• 择 zé = 2nd tone

A rough pronunciation guide for English speakers:

• xuǎn: sounds a bit like shwen, but with the Mandarin x sound, which is lighter and more fronted than English sh
• zé: roughly like dzuh with a rising tone

The x in xuǎn is one of the trickier sounds for English speakers. It is pronounced with the tongue closer to the front of the mouth than English sh.

It is pronounced:

• xǐ yī chéng xù

Tone pattern:

• 洗 xǐ = 3rd tone
• 衣 yī = 1st tone
• 程 chéng = 2nd tone
• 序 xù = 4th tone

A quick rhythm guide:

• xǐyī: wash clothes / laundry
• chéngxù: program / procedure

One useful note: when a 3rd tone is followed by a 1st tone, as in 洗衣, the first syllable is often pronounced as a low dipping tone, but in natural speech it may sound more like a low tone than a full dramatic dip.

Yes. It is a polite imperative sentence.

Mandarin often forms commands very simply:

• verb alone: 选择洗衣程序。 = Select the washing program.
• polite version with 请: 请选择洗衣程序。 = Please select the washing program.

Unlike English, Mandarin does not need a special verb form for commands. The base verb is used directly.

It is natural in the right context, especially on:

• appliance screens
• instruction manuals
• phone apps
• menu interfaces
• public notices

But in ordinary conversation, a person might say something a little different, depending on the situation. For example:

• 你选一下洗衣程序吧。 = Go ahead and choose the washing cycle.
• 先选择洗衣程序。 = First choose the washing program.
• 请选择要使用的洗衣程序。 = Please select the washing program you want to use.

So your sentence is very natural for a machine or written instruction, even if it is a bit more formal than casual speech.

Because none is needed here.

Classifiers are used mainly with numbers and demonstratives, such as:

• 一个程序 = one program
• 这个程序 = this program

But in 请选择洗衣程序, the noun 洗衣程序 is being used in a general sense, not counted or singled out with a demonstrative. So no classifier appears.

Yes. Depending on the context, all of these can work:

• washing program
• wash program
• wash cycle
• laundry program

For a washing machine, wash cycle is often the most natural everyday English translation. But program is also very common, especially in manuals and appliance interfaces.

So the Mandarin is flexible, and the best English wording depends on the product and style.