shìyòngqī shì sān gè yuè.

试用期 is a set phrase meaning probation period or trial period, especially in a job context.

You can roughly break it down like this:

• 试 = try, test
• 用 = use / employ
• 期 = period

But in real usage, you should learn 试用期 as one vocabulary item.

是 is the verb to be in a sentence that links one thing to another.

Here, the pattern is:

A 是 B
= A is B

So:

• 试用期 = the probation period
• 是 = is
• 三个月 = three months

So the structure is simply:

试用期 是 三个月。
The probation period is three months.

Chinese usually follows the basic order:

topic/subject + verb + complement

In this sentence:

• 试用期 is the subject/topic
• 是 is the linking verb
• 三个月 is what it is being identified as

So the normal order is:

试用期 + 是 + 三个月

That is the natural Chinese way to say The probation period is three months.

个 is a measure word.

In Chinese, numbers usually need a measure word before a noun. A very common pattern is:

number + measure word + noun

So:

• 三 = three
• 个 = measure word
• 月 = month

Together:

三个月 = three months

With 月, this is especially important because 三月 usually means March, not three months.

Usually, no.

• 三月 normally means March
• 三个月 means three months

So in this sentence, 三个月 is the standard and correct form.

If you say 试用期是三月, people will most likely understand it as The probation period is March, which is not what you want.

In English, we often say:

The probation period is three months long.

In Chinese, you usually do not need to add a word meaning long in this kind of sentence. Saying:

试用期是三个月。

already naturally means:

The probation period is three months long.

So Chinese often expresses this idea more directly than English.

Good question. The dictionary tone of 个 is fourth tone: gè. But in very common phrases like 三个月, native speakers often pronounce 个 lightly, almost as a neutral tone:

• careful citation: gè
• common speech: ge

So you will often hear:

sān ge yuè

That is completely normal.

Because 的 is not needed here.

的 is often used for possession or description, for example:

• 我的公司 = my company
• 重要的文件 = important document

But this sentence is a straightforward A is B sentence:

试用期 是 三个月。

There is no modifier relationship that requires 的.

In full, normal speech, 试用期是三个月 is the most standard form.

But in very short written notes, job ads, tables, or headings, you may see:

试用期三个月

This is a shortened, concise style. It means the same thing, but it feels more like a label or written note than a full sentence.

So:

• 试用期是三个月。 = full sentence, normal speech
• 试用期三个月 = shortened written style

You can think of it as both.

For a beginner, the simplest way is to call it the subject:

• 试用期 = subject
• 是 = verb
• 三个月 = complement

But from a more Chinese-focused grammar point of view, it is also the topic: the sentence is talking about the probation period and then saying what it is.

So if you are just starting out, treating it as the subject is perfectly fine.

A very common way is to add 吗 at the end:

试用期是三个月吗？
= Is the probation period three months?

Another common spoken pattern is A 是不是 B:

试用期是不是三个月？
= Is the probation period three months?

Both are natural.