The noun 'inn' begins with a vowel sound, so 'an' is correct. Indefinite articles are used when mentioning something for the first time. 'A inn' would be grammatically wrong. 'The inn' would imply a particular one already known. Therefore, 'an inn' is correct here.

Unique titles and religious designations always take 'the'. 'The Last Messenger of Allah' emphasizes that there is only one. 'A Last Messenger' or 'an Last Messenger' would be incorrect. 'No article' would make the title incomplete. Thus, 'the Last Messenger of Allah' is correct.

Although 'useful' begins with the letter 'u', it has a 'yoo' consonant sound. This requires 'a' instead of 'an'. 'An useful' would be grammatically wrong. Since the suggestion is introduced for the first time, the indefinite article is appropriate. Hence, 'a useful suggestion' is correct.

Rivers always take the definite article 'the'. The River Tigris is a specific and unique geographical name. 'A River Tigris' or 'an River Tigris' would be wrong. 'No article' would also make the phrase incomplete. Hence, 'the River Tigris' is correct.

The word 'essay' begins with a vowel sound, so 'an' is required. This is the first mention of the essay, so the indefinite article is appropriate. 'A essay' would be grammatically wrong. 'The essay' would mean one already specified earlier. Thus, 'an essay' is the correct choice.

Historical events are always referred to with the definite article 'the'. The Battle of Uhud is a unique event, so it must use 'the'. 'A Battle of Uhud' or 'an Battle of Uhud' would be incorrect. 'No article' would also leave the sentence incomplete. Therefore, 'the Battle of Uhud' is correct.

The word 'orange' begins with a vowel sound, so 'an' is correct. The fruit is being mentioned for the first time, making the indefinite article suitable. 'A orange' would be grammatically wrong. 'The orange' would mean one already known in context. Hence, 'an orange' is correct here.

Sacred religious texts such as the Hadith always require 'the'. This shows their uniqueness and significance. 'A Hadith' or 'an Hadith' would be ungrammatical in this context. 'No article' would also make the sentence incomplete. Thus, 'the Holy Hadith' is correct.

Superlatives such as 'tallest' always take the definite article 'the'. This is because they identify a single unique example among a group. 'A tallest girl' would be grammatically incorrect. 'No article' would also make the sentence incomplete. Therefore, 'the tallest girl' is correct.

Although 'European' begins with the vowel letter 'E', its pronunciation is 'yoo', which is a consonant sound. Therefore, 'a' is the correct article. 'An European' would be grammatically wrong. The jacket is mentioned for the first time, making the indefinite article suitable. Hence, 'a European jacket' is correct.