What is the ruling on a marriage ceremony in which the word Nikaah was not mentioned, as in the case in which American reverts say in English, “I officially take you as the head of my household,” or, “I make the union with you,“ etc. (but considering that all the requirements were met)? I ask because I read the hadith in which the Prophet, sallallahu 'alayhi wa sallam, said that marriage is valid even if a different word was used and the parties did not really intend to marry, so I wanted some clarification regarding that.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

The marriage is valid with the expressions mentioned in the question according to some scholars who do not stipulate a certain wording for Nikaah and, rather, take the customs of people in this regard into consideration. One of those scholars is Shaykh Ibn Taymiyyah who said, “Marriage takes place with any wording that the people consider as marriage in any language, any words, or any actions, and the same applies to any contract.”

He also said in response to those who stipulated mentioning the words Zawaaj, Tajweej, or Nikaah:

“What some companions of Maalik and Ahmad mentioned, that the marriage does not take place except with these two words, is far from their fundamentals (their principles in issuing rulings). A ruling is based on two introductions: First: we call this a metaphor, and the metaphor lacks intention. Their well-known view is that the indications of circumstances in metaphors make them explicit and that they substitute expressing the intention. It is for this reason that metaphors in divorce, in accusing someone of Zina (adultery) and the like, along with the prevailing circumstances, are considered to be like explicit expressions.

The circumstances surrounding a marriage, such as the people gathering for this purpose and their talking about it, well-known and then if after this he (the bride's guardian) says, ‘I give her to you (Arabic: Mallaktukaha) for 1000 dirhams,’ then the attendees automatically know that what is meant is marrying her off (for a dowry of 1000 dirhams). This wording is popular in the customs of the people until they named its contract ‘owning’ (Imlaak or Milaak).”

Mentioning the words Tazweej or Nikaah in the contract, even in non-Arabic, or even only in meaning, is better in order to avoid the difference of opinion. Most scholars are of the view that if someone does not know how to say these words in Arabic, then they are valid if he says them or what indicates their meaning in his own language.”

The Kuwaiti Fiqh Encyclopedia reads, “The majority of the scholars held that if someone does not speak good Arabic, it is valid for him to conduct the marriage contract in his language because he is incapable of saying it in Arabic, so he is excused just like a mute person, but he needs to use words that bear the same meaning of the Arabic words...” 

Allah knows best.