zhè shì kèfúdiànhuà.

这 means this.

In this sentence, 这 stands alone as a pronoun, so it means this or this thing:

• 这是客服电话。 = This is the customer service phone number.

If 这 comes before a noun, it usually works like this + noun, often with a measure word:

• 这个电话 = this phone
• 这个号码 = this number

But here, 这 is not directly modifying a noun. It is the subject of the sentence, so this is a natural translation.

是 is the verb to be in this sentence. It links 这 and 客服电话:

• 这 = this
• 是 = is
• 客服电话 = customer service phone number / customer service line

So the basic pattern is:

• A 是 B = A is B

This is one of the most common sentence patterns in Mandarin.

Examples:

• 这是老师。 = This is a teacher.
• 这是我的手机。 = This is my phone.

In this sentence, no. You do not need a measure word because 这 is being used by itself as a pronoun:

• 这 是 客服电话。

If you want 这 to directly modify a noun, then you usually need a measure word:

• 这个电话 = this phone
• 这个号码 = this number

So compare:

• 这 是 客服电话。 = This is the customer service phone number.
• 这个电话是客服电话。 = This phone number is the customer service number.
  (depending on context)

A very common learner mistake is to think 这 must always be 这个. It does not.

Yes, 客服电话 is commonly treated as a compound noun.

It can be understood in parts:

• 客服 = customer service
• 电话 = telephone / phone call / phone number

So:

• 客服电话 = customer service phone number / customer service line / customer service hotline

Also, 客服 itself is a shortened form of:

• 客户服务 = customer service

Chinese often makes compact compound nouns like this, so it is very natural to put the words together without extra linking words.

Because 客服电话 is a fixed noun phrase or compound, not a full possession phrase.

English often uses of or apostrophe-like relationships:

• customer service phone number
• the phone number for customer service

In Chinese, nouns are often simply placed together to form a compound:

• 客服 + 电话 → 客服电话

You do not normally say:

• 客服的电话

unless you specifically mean something like the phone belonging to customer service in a more literal or contextual sense.

So in this sentence, 客服电话 without 的 is the most natural form.

Yes, 电话 can mean several related things depending on context:

• telephone / phone
• phone call
• sometimes phone number

In 客服电话, it often refers to the customer service phone line or phone number.

If you want to be extra explicit, you can also say:

• 客服电话号码 = customer service phone number

But in everyday Chinese, 客服电话 is already very natural and commonly understood.

With pinyin and tones:

• 这 — zhè (4th tone)
• 是 — shì (4th tone)
• 客服电话 — kèfúdiànhuà

Tone breakdown:

• 客 kè — 4th tone
• 服 fú — 2nd tone
• 电 diàn — 4th tone
• 话 huà — 4th tone

A rough pronunciation guide:

• zhè sounds a bit like juh with a falling tone, but with the tongue curled back slightly
• shì sounds somewhat like shir (without a strong r), also with a falling tone

Natural rhythm:

• Zhè shì kèfúdiànhuà.

Because 这 and 是 are both 4th tone, each one falls sharply.

The structure is:

• 这 + 是 + 客服电话
• subject + to be + noun

So it follows a very basic identification pattern:

• This is X.

You can use this pattern with many nouns:

• 这是水。 = This is water.
• 这是我的名片。 = This is my business card.
• 这是公司地址。 = This is the company address.

It is a very useful beginner pattern in Mandarin.

Yes, very easily. The most common way is to add 吗 at the end:

• 这是客服电话吗？ = Is this the customer service phone number?

You can also answer:

• 是。 = Yes.
• 不是。 = No, it isn’t.

Another possible question in context would be:

• 这是什么？ = What is this?

Answer:

• 这是客服电话。

Yes. Depending on context, you might also hear:

• 这是客服电话。
• 这是客服电话号码。
• 这是客服的电话号码。

Differences:

• 客服电话 — short, natural, common
• 客服电话号码 — more explicit: customer service phone number
• 客服的电话号码 — also clear, slightly more expanded

The original sentence is perfectly natural, especially in practical contexts like websites, forms, signs, or customer support information.

。 is the Chinese full stop, equivalent to the English period .

So:

• 这是客服电话。

In typed Chinese, you normally use 。 instead of .

If you are just practicing vocabulary or writing notes by hand, leaving it off is not a big problem, but in normal written Chinese it should be included.