Learn Hardcore Japanese: watasi ha maiban nihongo wo benkyousimasu.

The grammatical subject of the verb is often omitted or marked with が, but in many everyday sentences the topic (～は) and the subject are the same person, so learners often think は = subject marker.

Rough idea:

私は毎晩日本語を勉強します。
→ As for me, (I) study Japanese every night.

Why is は pronounced “wa” here and not “ha”?

The character は is normally pronounced “ha” in words, but when it is used as the topic particle (like in 私は), it is pronounced “wa”.

So:

In a word: 花 (written with は in kana: はな) → hana (flower)
As a particle: 私＋は → pronounced watashi wa

This is just a historical spelling convention in Japanese. The same thing happens with:

へ (normally he) → as a direction particle, pronounced “e”
を (written wo) → pronounced “o”

Can I leave out 私は? Would 毎晩日本語を勉強します。 be correct?

Yes, you can absolutely leave out 私は, and it’s very natural to do so.

Japanese often omits things that are clear from context, especially the subject. If it’s already clear you are talking about yourself, you can just say:

毎晩日本語を勉強します。
→ I study Japanese every night.

Still correct, still polite.
Including 私は puts a bit more emphasis on “me (as opposed to others)”, or it might be used when you’re introducing a new topic: “As for me, I study Japanese every night.”

What exactly does 毎晩 (まいばん) mean? Is it the same as “every night” or “nightly”?

毎晩（まいばん） literally means “every night”.

毎 (まい) = every
晩 (ばん) = evening / night

Nuance:

Very close to English “every night” or “each night”.
It doesn’t usually sound exaggerated; it’s just a regular habit.

Related words:

毎日（まいにち） = every day
毎朝（まいあさ） = every morning
毎週（まいしゅう） = every week

In the sentence, 毎晩 is a time expression, modifying when you study.

What does the particle を do in 日本語を勉強します?

を marks the direct object of the verb.

日本語 = Japanese (language)
を = object marker
勉強します = (I) study

So 日本語を勉強します = study Japanese (literally, “Japanese (object) study”).

In English, the object is usually shown by word order:

I study Japanese. (Japanese = object)

In Japanese, word order is more flexible, so を is used to clearly mark what is being studied.

Why is the word order 私は毎晩日本語を勉強します? Can I move things around?

Japanese word order is more flexible than English. The basic rule is:

The verb comes at the end.
Particles (は, を, に, で, へ, から, まで, etc.) show each word’s role.

Your sentence:

私 (topic) は
毎晩 (time)
日本語 (object) を
勉強します (verb)

You can say, for example:

私は日本語を毎晩勉強します。
日本語を毎晩勉強します。
毎晩日本語を勉強します。

All are grammatically correct and mean essentially the same thing. The most natural/common patterns for a neutral sentence are:

(topic) は [time] [object を] [verb]
→ 私は毎晩日本語を勉強します。
or with omitted topic:
→ 毎晩日本語を勉強します。

Changing the order can add slight emphasis, but the meaning stays clear because of the particles.

Why isn’t there a word like “the” or “a” before 日本語? How do I know if it’s “Japanese” or “the Japanese language”?

Japanese does not have articles like “a / an / the”.

日本語 by itself just means “Japanese (language)” in a general sense. Whether you translate it as:

Japanese,
the Japanese language, or
Japanese language

depends on what sounds natural in English, not on extra words in Japanese.

Similarly, Japanese doesn’t mark singular/plural the way English does:

本を読みます。
Could be I read a book or I read books (in general).

Context usually tells you what is meant.

What exactly is 勉強します? Is 勉強 a noun or a verb?

勉強します is the polite verb form of 勉強する (to study).

勉強（べんきょう） by itself is a noun meaning “study / studying”.
In Japanese, many nouns become verbs by adding する (to do).
- 勉強する = to study
- 勉強します = polite form of 勉強する

So:

勉強 → study (the concept or act)
勉強する → to study
勉強します → I study / I will study (polite)

Does 勉強します mean “I study”, “I am studying”, or “I will study”?

勉強します can cover all of these, depending on context:

Habit / routine:
毎晩日本語を勉強します。
→ I study Japanese every night. (habitual)
Future:
今日、日本語を勉強します。
→ I will study Japanese today.
Right now (less common with simple ～ます, more natural with ～ています, but possible in context):
In a live commentary situation, 今、勉強します could be understood as I’m going to study now.

Japanese has a simple non-past tense (～ます / dictionary form) that usually covers present and future. For “I am studying (right now)”, Japanese often prefers:

今、日本語を勉強しています。
(literally: now, am in the state of studying Japanese)

How would I say this sentence in casual/plain speech instead of polite ～ます form?

The plain (dictionary) form of 勉強します is 勉強する.

So:

Polite:
私は毎晩日本語を勉強します。
Casual/plain:
俺は毎晩日本語を勉強する。 (for many males, casual)
私は毎晩日本語を勉強する。 (still fine, just less formal)
Or simply:
毎晩日本語を勉強する。

In very natural spoken Japanese, you might also hear the progressive/habitual:

毎晩日本語勉強してる。
(dropping を in speech is common, especially with short, clear sentences)

Choice of 私 / 僕 / 俺 and the exact style depends on gender, personality, and the relationship with the listener.

How do I say it in the past tense or negative?

Starting from 日本語を勉強します:

Past tense (polite):

日本語を勉強しました。
→ I studied Japanese.

With 毎晩:

私は毎晩日本語を勉強しました。
→ I studied Japanese every night.

Negative (present/future, polite):

日本語を勉強しません。
→ I don’t study Japanese / I won’t study Japanese.

With 毎晩:

私は毎晩日本語を勉強しません。
→ I don’t study Japanese every night.

Past negative (polite):

日本語を勉強しませんでした。
→ I didn’t study Japanese.

Same pattern works with 毎晩 as needed.

Could I use 日本語は instead of 日本語を? What’s the difference between 日本語は勉強します and 日本語を勉強します?

Yes, you can, but the nuance changes.

日本語を勉強します。
→ を marks 日本語 as the direct object.
→ Neutral: I study Japanese.
日本語は勉強します。
→ は marks 日本語 as the topic.
→ Nuance: As for Japanese, (I) do study it…
This often implies a contrast or emphasis, like:
- I don’t study Chinese, but Japanese I do study.

So:

日本語を勉強します。 — just telling you what I study.
日本語は勉強します。 — feels more like “At least Japanese, I study (maybe not other things)” or setting up a contrast.

How do I read this whole sentence, and what are the readings of the kanji?

The full reading is:

私は毎晩日本語を勉強します。
→ わたしはまいばんにほんごをべんきょうします。

Breakdown:

私 → わたし (watashi)
は (topic particle) → pronounced わ (wa)
毎晩 → まいばん (maiban)
日本語 → にほんご (nihongo)
を (object particle) → pronounced お (o)
勉強します → べんきょうします (benkyou shimasu)

Romanized in one line:

Watashi wa maiban Nihongo o benkyou shimasu.