English is the first language in Australia (Australian English), the Bahamas, Barbados (Caribbean English), Bermuda, Dominica, Gibraltar, Grenada, Guyana, Jamaica (Jamaican English), New Zealand (New Zealand English), Antigua, St. Lucia, Saint Kitts and Nevis, Saint Vincent and the Grenadines, Trinidad and Tobago, the United Kingdom (British English) and the United States of America (American English).
English is also one of the primary languages of Belize (with Spanish), Canada (with French), India (Hindi and English in addition to 17 other state languages), Ireland (with Irish), Singapore (with Malay, Mandarin, Tamil and other Asian languages) and South Africa (but Zulu, Xhosa, Afrikaans and Northern Sotho [combined?] are more spoken). It is the most commonly used unofficial language of Israel.
It is an official language, but not native, in Cameroon, Fiji, the Federated States of Micronesia, Ghana, Gambia, Hong Kong, Kiribati, Lesotho, Liberia, Kenya, Namibia, Nigeria, Malta, the Marshall Islands, Pakistan, Papua New Guinea, the Philippines, the Solomon Islands, Samoa, Sierra Leone, Swaziland, Tanzania, Zambia and Zimbabwe.
On this page you can find a lot of information about different English speaking countries that might be useful in your project work.