Learning English for the purpose of da’wah
Question

                What is your view on a seeker of knowledge learning English, especially if he wants to use it for da’wah and calling others to Allaah?
Praise be to Allah. 
          Shaykh Muhammad ibn Saalih al-‘Uthaymeen 
          (may Allaah have mercy on him) was asked this question. He replied as 
          follows. 
 
          Our view on learning English is that 
          it is a means and it is a bad menans if the aim is bad. But the one 
          thing that we must avoid is using it instead of Arabic. That is not 
          permitted. We have heard some foolish people speaking English instead 
          of Arabic, and some of the foolish people who are dazzled by the west, 
          whom I regard as lackeys (of the west), teaching their children to use 
          the greetings of the non-Muslims, and teaching them to say “bye-bye” 
          when departing, and so on. 
 
          Because using this language instead of 
          Arabic, which is the language of the Qur’aan and the noblest of languages, 
          is haraam. It was narrated that the salaf forbade speaking in the tongues 
          of the non-Arabs. 
 
          With regard to using it as a means of 
          da’wah, there is no doubt that this is obligatory sometimes. I did not 
          learn it and I wish that I had learned it. On some occasions I have 
          found forced to use an interpreter who could not fully express what 
          I wanted to say. 
 
          I will tell you a story of something 
          that happened to me in the mosque of Jeddah airport, with some men from 
          the Islamic Awareness organization. After Fajr prayer, we were speaking 
          about the Tijaani sect and how it is a false sect that that apostatized 
          from Islam. I started to say what I knew about them, then a man came 
          and asked me for permission to interpret my words into Hausa.  
          I gave him permission, and he started to interpret. Then a man came 
          rushing in and said, “This man who is interpreting for you is praising 
          the Tijaaniyyah.” I was astonished and I said, “Inna Lillaahi wa 
          inna ilayhi raaji’oon (Truly, to Allaah we belong and truly, to 
          Him we shall return).” If I had known this language I would not have 
          needed these cheaters. The point is that knowing the language of the 
          people whom you are addressing is undoubtedly important so that you 
          can convey the information to them. Allaah says (interpretation of the 
          meaning): 
 
          “And We sent not a Messenger except with 
          the language of his people, in order that he might make (the Message) 
          clear for them”
 
          [Ibraaheem 14:4]