It is believed by some people that primary school is the best place for learning a foreign language from scratch, whereas another approach is to begin in secondary school. While I think that firstly being in contact with a foreign language in high school may be of some benefits, I am more supportive of teaching it to the children in their primary years of education.
There are certain positive points to learning another language besides their native language in primary school. Firstly, in those first steps of learning, students are generally more fresh and ready to learn new materials. Secondly, studying it besides their mother tongue can help them to learn that better as well. Finally, as in their primary years young students are not under intense pressure from heavy course load, they have more free time to learn the new language and build a strong foundation, helping them enjoy the learning path with more comfort and ease.
Another view is that teaching a foreign language must start in later stages of general education. As secondary school students are already familiar with the sophisticated structure of their own language, it can help them learning another language with the help of this familiarity. In other words, they can compare and translate the new words into their native language and vice versa. However, all the positives aside, they may be reluctant or uninterested to start this new project at higher ages; and as mentioned earlier, other courses may take their time and prevent them from focusing with a free mind on their language course. Therefore, it may not be the best option for the students to begin familiarizing themselves with a new language when they are young adults.
In conclusion, I am more of the opinion that the sooner we initiate integrating foreign-language course materials in the school curriculums, the higher the chance that students learn it deeper and pay more attention to it.