a caballo regalado no le mires el diente significado en inglés

beggars can't be choosers▼(when resources are limited, one must accept even substandard gifts)
phrase
[UK: ˈbe.ɡərz kɑːnt bi ˈtʃuː.zə(r)z] [US: ˈbe.ɡərz ˈkænt bi ˈtʃuː.zərz]

don't look a gift horse in the mouth▼(a phrase referring to unappreciatively questioning of a gift or handout too closely)
phrase
[UK: dəʊnt lʊk ə ɡɪft hɔːs ɪn ðə maʊθ] [US: ˈdoʊnt ˈlʊk ə ˈɡɪft ˈhɔːrs ɪn ðə ˈmaʊθ]