"He does not doubt it."
Translation:Él no lo duda.
I believe, because we don't know the context of the sentence, "he does not doubt it (él no lo duda)", we do not know whether 'it' is an action or a fem./masc. thing. The best bet is to make 'it' gender neutral with 'lo'. There are no gender designations for verbs.
Context examples: If asked whether he doubts (¿Él duda...) the security of the train (...el seguridad del tren?), that the cat is going to drink (...si el gato/la gata va a beber?), or that he loves her (...si él la ama?), all three of these questions could individually be answered with, "He does not doubt it."
Native or more advanced Spanish speakers, please correct this or add to it if necessary. Thanks!
Your answer is right, but in your example "he doubts the security of the train", "security" is feminine in Spanish (la seguridad) and the verb "doubt" requires another word (preposition) next like: él duda DE/SOBRE la seguridad del tren.
Verbos como dudar, fiarse, sospechar, desconfiar, necesitan la preposición 'de' si van seguidos de un nombre (con o sin artículo)
In the others sentences you don't need to use 'de' after the verb 'dudar' because they are continued by the conjunction 'si' (whether) so it is usually omitted, although I think a better translation would be ...que +subjunctive... i.e.
Él duda (de) que el gato vaya a beber, Él duda (de) que (él) la ame.
I am learning English language. Corrections are welcome.
Note to self- Got this wrong. Remember to conjugate to third person - ar verb... 'a' present tense. Direct Object Pronoun is 'it' or in other words 'lo'. él is optional but use when sentence needs clarification. We don't need the personal 'a' because 'él is not an indirect object pronoun but the subject. Feel free to comment.
Haces bien en dudarlo, Talca.
Really "él no dúdalo" is grammatically correct although this way to speak Spanish is rarely used nowadays. It sounds a little archaic. Anyway, that way to speak, appending pronouns to verbs for any tense (not only infinitive or imperative), is commonly used yet in some places like here, in Asturias or the neighbor Galicia. People here say things like:
¿Tocote o tocarate? (¿te tocó o te tocará?) a lottery
but this is principally used with past tenses of verbs:
Esta mañana llamonos el jefe para una reunión = This morning the boss called us to a meeting;
and less with negative phrases, like this exercise.
In fact the most usual cliche (filler) used in these sites is ¿viste? (did you see?) like in Argentina, or ¿oíste? (did you hear?).
Créaslo o no, es cierto. ;-)