هي تضع الملابس في الغسالة.

Yes, it can be left out.

Arabic verbs already show the subject, and تضع already tells you the subject is she or you (masculine singular). So:

• هي تضع الملابس في الغسالة = She puts/is putting the clothes in the washing machine
• تضع الملابس في الغسالة can also mean the same thing if the context already makes she clear

Including هي often adds clarity, emphasis, or contrast, like she in she is the one putting the clothes in the washing machine.

In the present tense, Arabic uses prefixes on the verb.

For وضع (to put/place), the present forms include:

• أضع = I put
• تضع = you put (masculine singular) or she puts
• يضع = he puts
• نضع = we put

So تـ does not always mean you. In this sentence, the separate pronoun هي makes it clear that تضع means she puts / she is putting.

The dictionary form is the past-tense verb وضع, which means to put or to place.

Its root is و-ض-ع.

A common point of confusion is that the و from the root does not appear at the beginning of the present-tense form:

• وضع = he put
• يضع = he puts
• تضع = she puts

So if you are looking it up, search for وضع, not تضع.

It can mean either one.

In Modern Standard Arabic, the present tense often covers both:

• she puts
• she is putting

Context tells you which one is intended.

If you want to make right now especially clear, Arabic often adds a time word such as:

• الآن = now

So:

• هي تضع الملابس في الغسالة الآن = She is putting the clothes in the washing machine now

Because الـ makes the noun definite: the clothes.

• ملابس = clothes / clothing / some clothes
• الملابس = the clothes

Arabic uses definiteness a lot, just as English does, but not always in exactly the same places. Here, الملابس suggests specific clothes that both speaker and listener can identify.

It is plural.

ملابس is a broken plural, commonly used to mean clothes or clothing. A related singular form is ملبس, though in actual usage learners will most often meet ملابس as the everyday word for clothes.

So in this sentence:

• الملابس = the clothes

Literally, في means in.

So في الغسالة literally means in the washing machine.

With a verb like put, English often says put ... in ..., and that is exactly what Arabic does here too. In natural translation, this may feel like into in English, but the Arabic word used is still في.

الغسالة means the washing machine.

It comes from the root غ-س-ل, which is related to washing:

• غسل = to wash
• غسالة = washing machine

So:

• في الغسالة = in the washing machine

A careful fully vocalized version is:

هِيَ تَضَعُ الْمَلَابِسَ فِي الْغَسَّالَةِ

Those endings show grammar:

• تضعُ: the verb is in the indicative present, so it ends in -u
• الملابسَ: direct object, so it is accusative
• الغسالةِ: after في, it is genitive

In normal everyday Arabic writing, these short vowels are usually not written.

It is pronounced approximately taḍaʿu.

A few sounds may feel new to English speakers:

• ض is an emphatic d-like sound
• ع is a throat sound with no exact English equivalent

A reasonable learner-level approximation is something like ta-da-u, but if possible, try to learn the real ع sound early.

The whole sentence can be pronounced roughly as:

hiya taḍaʿu al-malābisa fī al-ghassālati

No. Arabic word order is flexible.

This sentence begins with the pronoun:

• هي تضع الملابس في الغسالة

That is perfectly correct and can give a slightly more topic-focused or emphatic feel: She is putting the clothes in the washing machine.

Very often, Arabic would simply say:

• تضع الملابس في الغسالة

because the verb already shows the subject.

So both are possible, but with slightly different emphasis.