Learn Arabic (Modern Standard): شاهد الرجل مباراة في التلفاز.

In Arabic, the standard sentence structure is Verb-Subject-Object (VSO). So instead of saying 'The man watched a match' like in English, we say 'Watched the man a match' (شاهد الرجل مباراة). This is the most common way to build a sentence that describes an action.

The English translation says 'on television', but doesn't في mean 'in'?

Yes, في literally translates to 'in'. However, prepositions rarely match up perfectly between languages. In Arabic, you watch things 'in' the television (في التلفاز), rather than 'on' it.

How do we know it means 'a match' and not 'the match'?

The word for match, مباراة, does not have the definite article الـ (al-) attached to the beginning. In Arabic, when a standard noun doesn't have الـ, it is indefinite, which we translate using 'a' or 'an' in English.

If the subject was a woman, would the verb شاهد change, even though it comes first in the sentence?

Yes! Even though the verb comes before the subject in VSO order, it still must match the subject's gender. If 'the woman' (المرأة) was watching, you would add a feminine 't' ending to the past tense verb, making it شاهدت المرأة.