المصدر واضح.

Because this is a nominal sentence in Arabic. In the present tense, Arabic usually does not use a separate word for is / am / are.

So:

• المصدر واضح
• literally: the source clear
• natural English: The source is clear

This pattern is extremely common in Modern Standard Arabic:

• البيت كبير = The house is big
• الجو جميل = The weather is nice

If you want the full grammatical terms, المصدر is the subject/topic (مبتدأ) and واضح is the predicate/comment (خبر).

Because المصدر is the definite noun the source, while واضح is the predicate adjective clear.

In Arabic nominal sentences, the predicate is often indefinite, so you commonly get this pattern:

• المصدر واضح
• الكتاب مفيد
• الطريق طويل

If you said المصدر الواضح, that would no longer mean The source is clear. It would mean the clear source, where الواضح is now an adjective directly describing the noun.

So the contrast is:

• المصدر واضح = The source is clear
• المصدر الواضح = the clear source

It is an adjective in form and meaning, but in this sentence it is functioning as the predicate of the sentence.

That means:

• as a word type: واضح = adjective (clear)
• as a sentence role: it is the predicate (خبر)

This is very common in Arabic. Adjectives can be used as predicates without any extra word:

• الرجل طويل = The man is tall
• الجو بارد = The weather is cold

So واضح is not modifying المصدر the way an attributive adjective would. It is telling us something about it.

In full vowelled Arabic, it is:

• المصدرُ واضحٌ

Why?

• المصدرُ is the subject/topic of the nominal sentence, so it is nominative
• واضحٌ is the predicate, and it is also nominative

So the full pronunciation in careful reading is:

• al-maṣdaru wāḍiḥun

In normal pause, especially at the end of a sentence, those final short vowels are usually not pronounced, so you often hear something closer to:

• al-maṣdar wāḍiḥ

A helpful pronunciation guide is:

• المصدر = al-maṣdar
• واضح = wāḍiḥ

A few sounds may need attention:

• ص in مصدر is an emphatic s
• ض in واضح is an emphatic d-like sound
• ح in واضح is a voiceless throat sound, not the ordinary English h

Also, the الـ in المصدر is pronounced clearly as al- because م is a moon letter, not a sun letter.

• المصدر comes from the root ص د ر and commonly means source, and in grammar it can also mean verbal noun / infinitive-like noun
• واضح comes from the root و ض ح, which has the basic idea of being clear, evident, visible

Knowing roots helps you connect related words. For example, from و ض ح you may also meet words related to clarity or explanation.

It can mean more than one thing depending on context.

Common meanings include:

• source
• origin
• in grammar: maṣdar, the verbal noun

So if you see المصدر in a textbook, it may not mean a physical or informational source. It could be a grammar term.

That is why context matters a lot with this word.

It is masculine because المصدر is a masculine singular noun, and predicate adjectives normally match in gender and number.

So:

• المصدر واضح
• not المصدر واضحة

If the noun were feminine, you would use the feminine form:

• الصورة واضحة = The picture is clear

So yes, واضحة is possible, but only with a feminine noun.

Yes, but المصدر واضح is the most straightforward and neutral order.

Arabic often uses:

• subject + predicate
• المصدر واضح

Other orders can happen for style, emphasis, or specific contexts, but they may sound more literary or marked to a learner.

For basic Modern Standard Arabic, treat المصدر واضح as the standard pattern to imitate.

This is one of the most important distinctions to notice.

• المصدر واضح = a full sentence
  • The source is clear
• المصدر الواضح = a noun phrase
  • the clear source

In the sentence version:

• واضح is the predicate
• it is usually indefinite

In the noun-phrase version:

• الواضح is an adjective modifying المصدر
• it matches it in definiteness, so both have الـ

This is a very common contrast in Arabic, and learning it early is extremely useful.