Tajweed consists of two parts which related to the essence of their meaning:

Information may not be reliable

The Scientific Tajweed: It is the knowledge of Tajweed rules and characteristics in the certified books. This part is a collective duty which means if a few Muslims learn and memorize it, it was made to fall from the others; but if no one does then all the Muslims are in sin. That is because it is one of the legal science and for that, there is a MUST to be in each of the Islamic countries of different languages tutors taught it. Allah Almighty said," And it is not for the believers to go forth [to battle] all at once. For there should separate from every division of them a group [remaining] to obtain understanding in the religion and warn their people when they return to them that they might be cautious." [Quran, At-Tawba-122]

The Practical Tajweed: It is the implementation of phonetic rules of Quranic recitation and reading Quran with tajweed as it was revealed to the Prophet Muhammed (Peace be upon him). It is required upon every legally competent Muslim of a responsible age to perform religious duties in Islam and to recite Quran with tajweed properly. Allah Almighty said, "….And recite the Quran with measured recitation." [Quran, Al-Muzzammil-4]

Levels of Reciting (Tajweed) the Holy Quran

There are three levels of recitation that exist in tajweed. They are classified according to the human ear which can only recognize them as a slow recitation, a fast recitation and a moderate recitation (neither slow nor fast).

A-Tahqîq: (slowness without elongation), which is the slowest recitation without elongation that encourages to reflect upon the words and meanings and that allows hearing the tajweed rules very clearly. This level exemplified by the simplicity and care in articulating the letters of Quran words.

Quran Tajweed Rules

Al-Hadr: (fast reading without merging of the adjacent letters), which is a quick recitation that utilized for revision; thus it is very close to everyday speech rhythm. When reading with Hadr, there is a danger of minimizing the timing of the letters and merging one into another. However, there is no problem with reciting the Quran with Hadr, provided that there is no idghaam (merging of the adjacent letters) or reduction in the required time of the letter articulation.

At-Tadweer: (letters moderation in recitation), which is reading in between Al-hadr and Al-Tahqiq, neither too fast nor too slow.

Common Tajweed Mistakes

It is vital that the Muslims learn the Arabic letters and vowels to recite the Quran using them, not a transliteration. Transliterations do not take into consideration the several letters that sound similar to the untrained ear but are very different in pronunciation. The Quran is the word of Allah, revealed to man as a guide, and we have to be extremely careful when reading it, as best we can, with proper pronunciation. Reading a transliteration can lead to a change in the meaning of the Holy Quran by mispronouncing its Arabic letters.

The most critical mistakes Muslims do when reciting the Holy Quran are:

The first mistake, made by Arab and non-Arab Muslims alike, is in making inappropriate starts and stops. There are two issues of this mistake. The first issue is that the appropriate way to stop on a word is by putting a sukoon, or absence of a vowel on the last letter of the word. It is not permitted to stop using the harakah, or vowel on the last letter of the word. The second issue of stopping is that of stopping at a place that does not contradict the meaning intended by Almighty Allah, the Exalted. The same mistake can occur when starting up after stopping and taking a breath. We cannot just start on the next word at random, that is; the meaning needs to be considered, and the start should be on a word that represents the absolute and perfect meaning, even if the reader needs to go back two or three words.

There are two most common tajweed mistakes made by non-Arabs: the timings of the vowels (madd letters in Arabic) and in the articulation points of the letters.

The first type concerning the timing of the vowels (i.e. lengthening a vowel longer than one vowel count), and natural lengthening (making them shorter than they should be). Each vowel over a letter receives one count.So a kasrah receives the same timing as a fath, as does a dhammah, whenever these letters are not followed by the madd letters alif; or a ya' with no vowel preceded by a kasrah, or wow with no vowel preceded by a dhammah). Whereas Madd letters have two vowel counts if they are not followed by a hamzah or a sukoon. All vowels, as stated above, have equal timing in length. This is not true for letters without vowels or saakin letters.The timings of saakin letters vary depending on their characteristics.The difference is in not a great length of time, though.