We all know that Allah says that he is the king of the kings but i accidentally said that Allah is the kings of the kings i accidentally said kings instead of king..is this shirk? I said shahada and did tawbah and i got scared and keept asking for forgiveness...is this shirk? Will Allah forgive me for just doing a grammar mistake? I repeated the shahada also so will Allah forgive me? Also i am shirk and kufr thoughts in my mind and i ignore them am i a sinner for that?
the mercy of Allah the mighty and sublime is endless, let not shaithaan guide you to hopelessness. hold fast unto your faith and keep believing in the quran and authentic sunnah.
On the authority of Ibn Abbas (may Allah be pleased with him), that the Messenger of Allah (peace and blessings of Allah be upon him) said:
Verily Allah has pardoned [or been lenient with] for me my ummah: their mistakes, their forgetfulness, and that which they have been forced to do under duress.
[A hasan hadeeth related by Ibn Majah, and al-Bayhaqee and others]
[Reference: Hadith 39, 40 Hadith an-Nawawi]
this hadith lays the foundations for the answer of your question. i will mention more verses from the glorious quran just to make things more clear to you and in the hope of you finding contentment, insha Allah.
"Our Lord, do not impose blame upon us if we have forgotten or erred" [2:286]
"And there is no blame upon you for that in which you have erred but [only for] what your hearts intended. And ever is Allah Forgiving and Merciful." [33:5]
Say, "O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful." [39:53]
always remember that shaithaan will always try to creep into our thoughts and create doubts about our belief in our Rabb. do not harbor and give much concern to such wasteful thoughts. we as humans sometimes might do things that are not right, it necessarily doesn't have to be shirk or kufr.
"forgetfulness means that the person is aware of something but later becomes oblivious of it during the action. Both mistakes and acts of forgetfulness are pardoned; meaning that the person bears no sin for them."
[Jaamiʻ Al-ʻUloom wa Al-Hikam]
may Allah grant you mercy and guide you to the straight path.
Allah knows best.