אני לא בטוח שהתשובה הזאת נכונה.

In Hebrew, the verb to be is usually omitted in the present tense.

So instead of saying the answer is correct, Hebrew says literally:

• התשובה הזאת נכונה = the answer this correct

This is completely normal Hebrew.
If you wanted past or future, then Hebrew would use a form of to be:

• התשובה הזאת הייתה נכונה = This answer was correct
• התשובה הזאת תהיה נכונה = This answer will be correct

Just like in the second part of the sentence, Hebrew often leaves out am/is/are in the present tense.

So:

• אני בטוח = I am sure
• אני לא בטוח = I am not sure

Literally, it is more like:

• I not sure

But in natural English we translate it as I’m not sure.

Because it agrees with the speaker.

In Hebrew, adjectives change for gender.
בטוח is masculine singular, so this sentence is being said by a male speaker.

• Male speaker: אני לא בטוח
• Female speaker: אני לא בטוחה

So if a woman were saying the sentence, it would be:

• אני לא בטוחה שהתשובה הזאת נכונה

Because it describes התשובה, and תשובה is a feminine noun.

Hebrew adjectives must agree with the noun they describe in gender and number.

• תשובה = feminine singular
• therefore נכונה = feminine singular adjective

Compare:

• התשובה נכונה = The answer is correct
• הספר נכון would be wrong, because ספר is masculine, so it should be נכון

ש־ means that in this sentence.

It introduces a subordinate clause:

• אני לא בטוח = I’m not sure
• שהתשובה הזאת נכונה = that this answer is correct

So the full structure is:

• אני לא בטוח ש... = I’m not sure that...

This ש־ is very common in Hebrew and often attaches directly to the next word.

Because ש־ is usually written as a prefix attached to the following word.

So:

• ש + התשובה → שהתשובה

This is normal Hebrew spelling. The same thing happens with other short prefixes such as:

• ו־ = and
• ב־ = in
• ל־ = to
• כ־ = as / like
• ה־ = the

Hebrew often combines these small particles directly onto words.

In Hebrew, demonstratives like this usually come after the noun.

So Hebrew says:

• התשובה הזאת = literally the answer this

This is the normal word order.

Other examples:

• הספר הזה = this book
• הילדה הזאת = this girl

Notice that the demonstrative also agrees in gender and number with the noun:

• הזה = masculine singular
• הזאת = feminine singular

Since תשובה is feminine singular, Hebrew uses הזאת.

Yes. Both are correct and common.

• התשובה הזאת
• התשובה הזו

Both mean this answer.

Very roughly:

• הזאת can sound a bit fuller or slightly more formal in some contexts
• הזו is also extremely common in everyday speech and writing

A learner should understand both.

In Hebrew, when you say this/that with a noun, the noun is normally definite, so it usually takes ה־.

That is why Hebrew says:

• התשובה הזאת = this answer

not usually:

• תשובה הזאת

This is different from English, where this already makes the noun definite by itself.
In Hebrew, the pattern is generally:

• ה + noun + demonstrative

Examples:

• הבית הזה = this house
• המכונית הזאת = this car

The adjective בטוח can mean both sure/certain and safe/secure, depending on context.

Here, because the sentence is about an answer being correct, בטוח clearly means sure/certain:

• אני לא בטוח = I’m not sure / I’m not certain

In a different context, it could mean safe:

• המקום הזה לא בטוח = This place is not safe

So the meaning depends on what is being discussed.

The sentence has two main parts:

1. אני לא בטוח = I’m not sure
2. שהתשובה הזאת נכונה = that this answer is correct

So the overall pattern is:

• [speaker] + not sure + that + clause

This pattern is very common in Hebrew:

• אני חושב ש... = I think that...
• אני יודע ש... = I know that...
• אני לא בטוח ש... = I’m not sure that...

The given order is the most natural and neutral one:

• אני לא בטוח שהתשובה הזאת נכונה

Hebrew can sometimes move things around for emphasis, but for a learner this is the standard pattern to use.

For example, you might occasionally hear emphasis on התשובה הזאת, but the neutral sentence is exactly the one you were given.

So as a beginner or intermediate learner, it is best to stick with:

• אני לא בטוח ש...

followed by the clause.

Only בטוח changes, because it describes the speaker.

A woman would say:

• אני לא בטוחה שהתשובה הזאת נכונה

The rest stays the same, because התשובה is still feminine singular, so הזאת and נכונה do not change.

It is pronounced roughly she-ha-tshu-va.

What is happening is:

• ש־ = she
• התשובה = ha-tshuva

Together:

• שהתשובה = sheha-tshuva

In normal speech, it flows as one unit because Hebrew attaches ש־ to the following word in both writing and pronunciation.