kono kikai ha gamen mo ookiisi, tezyundoori ni tukaeba sorehodo muzukasiku arimasen.

は marks この機械 as the topic of the sentence: as for this machine...

That means the speaker is giving information about this machine. In English, we often do this without any special marker, but Japanese marks it clearly.

If you changed it to が, the nuance would be different. が would sound more like identifying this machine specifically, while は is natural when describing its features.

も means also or too.

So 画面も大きいし suggests that the screen is also big. It sounds like the speaker is listing one good point in addition to another point, either stated later or understood from context.

In other words, も gives the feeling that a large screen is one of several positive aspects.

〜し is used to connect reasons, examples, or supporting points.

Here, 大きいし has a nuance like:

• it’s big, and...
• for one thing, it’s big...
• it’s big, plus...

So the speaker is not just stating one fact. They are building a case. In this sentence, the large screen is one supporting point, and the rest of the sentence adds another point.

A useful thing to remember is that 〜し often implies there may be other reasons too, even if they are not all fully stated.

Because し attaches to the plain form of the adjective.

For an い-adjective like 大きい, the plain form is 大きい, so:

• 大きい + し → 大きいし

大きく is the adverbial form, so it is used in different patterns, such as:

• 大きくなる = become big
• 大きく書く = write largely

But with し, you use the plain form, so 大きいし is correct.

手順どおりに is made of:

• 手順 = procedure, steps
• どおり = in accordance with, following
• に = makes the phrase act adverbially

So grammatically, 手順どおりに means according to the procedure or following the steps.

It describes how the machine should be used. In this sentence, it modifies 使えば.

You can think of Noun + どおりに as a useful pattern:

• 説明どおりに = as explained
• 予定どおりに = as planned
• 手順どおりに = according to the procedure

使えば is the ば-conditional form of 使う.

Formation:

• 使う → 使えば

It means if you use it.

In this sentence, it expresses a condition:

• if you use it according to the steps, it is not that difficult

The ば form often sounds neutral and natural for general conditions like this.

Japanese often leaves out the subject when it is obvious or not important.

Here, the subject is understood from context. It could mean:

• if you use it
• if one uses it
• if it is used

In natural English, we usually supply you, but Japanese does not need to say it explicitly.

This kind of omission is extremely common, so learners should get used to understanding the subject from context rather than expecting it to be stated every time.

それほど means to that extent or that much.

When it is used with a negative, as in:

• それほど難しくありません

it means:

• it’s not that difficult
• it’s not so difficult

So the sentence is not saying the machine is easy in an absolute sense. It is saying it is not especially difficult, especially if used properly.

This is a common pattern:

• それほど〜ない = not that ~

難しくありません is the polite negative form of the い-adjective 難しい.

Formation:

• 難しい
• remove い → 難し
• add く → 難しく
• add ありません → 難しくありません

So:

• 難しい = difficult
• 難しくありません = is not difficult

This is a standard polite form.

You may also hear 難しくないです, which is also common in modern Japanese conversation. Both are polite, but 難しくありません can sound a little more formal or textbook-like.

It is somewhere between the two.

In many cases, 〜し can be translated as either:

• and
• because
• for one thing...

In this sentence, it is connecting supporting points, so it has both a listing feel and a reasoning feel.

So 画面も大きいし is not just a plain connection like and the screen is big. It sounds more like:

• the screen is big, and that’s one reason...
• for one thing, the screen is big...

That is why 〜し is very useful when giving explanations or persuasive reasons.